Reading Comprehension Passage Topics

Below, I've listed every LSAT Reading Comprehension passage topic from every released LSAT PrepTest.

Best LSAT Prep Books lists the books containing these exams. You can also see most of these passages categorized by topic.

PrepTest A - February 1996
1. Medieval marriage practices, Alexandrine doctrine
2. Nontraditional black women filmmakers
3. Alfred Wegener's theory of continental drift
4. Jose Antonio Maravall's interpretation of Baroque culture


PrepTest B - February 1999
1. Invertebrate schooling behavior and benefits
2. Rationales for punishing criminals, social-benefit vs. retributivist
3. Hispanic American writers and Spain, cosmopolitanism vs. nativism
4. Privileged Renaissance women's education


PrepTest C - February 2000
1. Kinglets' survival in cold winters
2. Juvenile delinquency
3. African American communism in Alabama, Robin Kelley's Hammer and Hoe
4. Darwin's conception of early prehistoric humans, and taphonomy


Official LSAT PrepTest - February 1997
1. Childhood in medieval Europe, Philippe Aries vs. Shulamath Shahar
2. Greenhouse gases and impact
3. 19th-century British feminists and legal/labor historians
4. Robert L. Jackson's Black Writers in Latin America


PrepTest 1 - June 1991
1. Phillis Wheatley, African American poet/poetry
2. Cell biology / cytology and biochemistry
3. Criminal procedure - adversarial vs. inquisitorial systems
4. Professions - defining the term


PrepTest 2 - October 1991
1. Langston Hughes and folk poetry
2. U.S. railroad, "romantic-era distrust" of it, John Stilgoe
3. Water-bug adaptive responses, micropterous, macropterous
4. War Powers Resolution


PrepTest 3 - December 1991
1. Asteroid satellites
2. English scientists not crediting technicians for their work
3. Abuse of monopoly power
4. Navajo weaving, Amsden


PrepTest 4 - February 1992
1. Territorial waters, regulation of international waters
2. Biological diversity and human activity
3. Women's participation in French Revolution
4. French Impressionism, Robert L. Herbert


PrepTest 5 - June 1992
1. Administrative contracts and altering contracts unilaterally
2. Nico Frijdas "law of apparent reality" and emotional responses to art
3. Bacteria and chemical attractants, concentration gradient
4. Life-passage vs. life-history studies


PrepTest 6 - October 1992
1. Taft-Hartley Act, "right-to-work" legislation, Thomas M. Carroll
2. Women physicians in China
3. Early music movement
4. U.S. steel industry


PrepTest 7 - February 1993
1. Working mothers in the labor force
2. John Webster, Elizabethan playwright, and critics
3. Phytopathogens, pseudomonas fluorescens / syringae
4. Native American land and the Dawes Act


PrepTest 8 - June 1993
1. Recombinant DNA (rDNA)
2. Gray marketing
3. African American autobiographical narratives
4. British wealth, Rubinstein's claim


PrepTest 9 - October 1993
1. Technology and art, video, photography
2. Native Americans, land, readjustment, Bureau of Indian Affairs
3. Literacy in Ancient Greek society and the elite
4. Political attitudes / institutions in England vs. American colonies


PrepTest 10 - February 1994
1. Crude oil pumps and offshore processing platforms
2. Venetian religious narrative painting, Patricia Fortini Brown
3. Legal realists and vagueness in law
4. Civil rights movement social theories


PrepTest 11 - June 1994
1. Martin Luther King, Thoreau, and transcendentalism
2. Robert Dahl, democracy, and polyarchy
3. Species diversity in Amazon River basin
4. Women medical practitioners in Europe during Middle Ages


PrepTest 12 - October 1994
1. Otto Wagner's Modern Architecture
2. Socioeconomic achievements on Chinese and Japanese immigrants
3. Legal systems in US vs. England - substantive vs. formal reasons
4. Serotonin and carbohydrate craving


PrepTest 13 - December 1994
1. Neurogenesis and canaries
2. Freed African Americans in colonial Virginia, Myne Owne Ground
3. French artist Watteau and admirers
4. Jury inferential errors


PrepTest 14 - February 1995
1. Earth's magnetic field - hypotheses
2. Deconstruction - term and meaning
3. Stolen art, legislation, and purchasers
4. Russian serfdom vs. U.S. slavery, Peter Kolchin


PrepTest 15 - June 1995
1. Dinosaur extinction, volcanic-eruption theory vs. impact theory
2. Women folklorists
3. J.G.A. Pocock and political discourse
4. Black economic progress - hypotheses


PrepTest 16 - September 1995
1. Byron's poetry and personality
2. Native Americans and Supreme Court decisions
3. Large interactive systems, catastrophe caused by minor events
4. Women in colonial America vs. England


PrepTest 17 - December 1995
1. Zora Neale Hurston's Their Eyes Were Watching God
2. "Hard" legal cases, H.L.A. Hart vs. Ronald Dworkin
3. Industrial carbon dioxide emissions, impose a tax
4. Drought in sub-Saharan West Africa


PrepTest 18 - December 1992
1. Law-and-literature movement, Richard Posner
2. Science - objective vs. ideological bias (subjective), new historians
3. Cherokee and Euro-American culture, William McLoughlin
4. Luminist paintings, Fitz Hugh Lane


PrepTest 19 - June 1996
1. P.D. James' crime novels
2. Native American graves, individual vs. communal property law
3. Species diversity hypotheses
4. Britain's abolition of the slave trade, Eric Williams


PrepTest 20 - October 1996 - Free Online (PDF)
1. Miles Davis and jazz innovation
2. Medieval canon lawyers and lack of disciplinary proceedings
3. Birds and status signaling hypothesis, Rowher
4. Collapse of Classic Mayan civilization, John Lowe


PrepTest 21 - December 1996
1. London Pianoforte school and Nicholas Temperley's anthology
2. What is "law"? Law and Economics, Critical Legal Studies, Law and Lit
3. Origin of oil - biogenic vs abiogenic theory
4. Southeast Asian immigrants and James Tollefson's Alien Winds


PrepTest 22 - June 1997
1. Frida Kahlo and Mexican nationalism
2. Objectivism vs. alternative legal narratives
3. CEOs' economic vs. moral responsibility
4. Language and math, essentialist vs. conventionalist views of language


PrepTest 23 - October 1997
1. Dutch artist Rembrandt as entrepreneur, Svetlana Alpers
2. Medieval women's legal / financial rights
3. Environmental crisis, George P. Marsh, Frederic Clements
4. Fugita and O'Brien's Japanese American Ethnicity


PrepTest 24 - December 1997
1. Risk communication
2. Korean Americans, cultural identity, Pico Korea Union
3. Social science tools to analyze court opinions
4. Mark Jones's Fake? The Art of Deception (fake art)


PrepTest 25 - June 1998
1. Email privacy and the law
2. Homer's poetry - studying works vs. peripheral issues, Milman Parry
3. Native American intertribalism, Pan-Indian view
4. Analytic method vs. organicism


PrepTest 26 - September 1998
1. Compulsory national service
2. James Porter and African influence on African-American art
3. Dolphin die-off, PCBs, brevetoxin, synthetic pollutants
4. English marriage contracts and women's property rights, Susan Staves


PrepTest 27 - December 1998
1. Jury impartiality, judges, media coverage, voir dire
2. Personal names in Hopi culture
3. Homing pigeons - hypotheses re: how they "home"
4. Fairy tales, Bruno Bettelheim, Freud, therapeutic


PrepTest 28 - June 1999
1. Native American land claims, Mashpee, legal discourse
2. Volcano-climate connection, Mass and Portman
3. Steady-state economics vs. neoclassical economics
4. Movie quality/promotion changes due to mass media


PrepTest 29 - October 1999
1. Are pre-World War I painters prophetic?
2. Tribal communities in North America, and teaching traditional languages
3. Platypus uses bill to locate prey
4. Medieval law and women, lack of knowledge


PrepTest 30 - December 1999
1. The okapis' relatives, size and location of population, eating behavior
2. Greek tragic dramas, and free will vs. gods and fate
3. Denise Meyerson vs. Critical Legal Studies
4. Vernon and African American rice cultivation


PrepTest 31 - June 2000
1. Ideal industrial ecosystem and Earth's population increase
2. Thurgood Marshall's legal career and his strategies / approaches
3. Donna Haraway's Primate Visions
4. Objectivism vs. subjectivism when studying the mind


PrepTest 32 - October 2000
1. Defense lawyers and innocence/guilt of clients, obligations
2. Multicultural education and proposals for implementation.
3. Native American autobiographies
4. Why wine is healthy in moderation


PrepTest 33 - December 2000
1. Per capita GNP vs. human indicators, measuring a nation's economic health
2. Harriet Jacobs' autobiographical narrative, slave women, domestic novel
3. Potential benefits of increased atmospheric CO2 levels / concentrations
4. Jeremy Bentham and evidence reform - nonexclusion principle


PrepTest 34 - June 2001
1. Authoritarian rulers and democratic reforms/change
2. The blues, African American folk tradition, and spirituals
3. Lamarck and the inheritance of acquired characteristics - new examples
4. Women refugees and definitions according to the United Nations


PrepTest 35 - October 2001
1. Women's memoirs of the French Revolution, Denis Bertholet's study
2. Romare Bearden, paintings, and the African-American experience
3. Universal laws, determinism, and biology
4. Ronald Dworkin, legal positivism, and natural law


PrepTest 36 - December 2001
1. Do computer conferences function as communities?
2. Latin texts in Renaissance England
3. Hormones, behavior, and osmolality
4. South Africa's legal system and change


PrepTest 37 - June 2002
1. Jury trials, unanimity requirement
2. Marie Curie, radiation/radioactivity
3. Ralph Ellison, Invisible Man, critics
4. Psychology of decision making, and risk-taking


PrepTest 38 - October 2002
1. Native Americans and controlled burning of forests
2. Intellectual authority vs. institutional authority. Legal systems.
3. Philip Abrams, historical sociology, and structuring
4. Medical school ethics training


PrepTest 39 - December 2002
1. Muralists - Mexican artists / painters
2. Interpreting fairy tales, parents vs. children, Bruno Bettelheim
3. Max Planck, wave theory, and radiation
4. Canadian copyright law and digitalization


PrepTest 40 - June 2003
1. Multipolar vs. bipolar international political systems
2. Latin American poetry vs. Spanish poetry
3. Dark matter and neutrinos' mass
4. Leading questions and memories


PrepTest 41 - October 2003
1. Course packs and copyright law
2. Countee Cullen - Harlem Renaissance poet, European-style verse
3. Fossil fuels and renewable energy sources
4. Victorian philanthropy and criticism of it


PrepTest 42 - December 2003
1. Thurgood Marshall, NAACP, public interest law, tactics/strategies
2. Roy Lichtenstein, fine art, pop art, comics
3. Market system and technological developments
4. Neurotransmitters, synapses, and electrical impulses


PrepTest 43 - June 2004
1. Oil well drilling and contaminated groundwater
2. Code-switching among Puerto Rican Americans
3. Reader-response theory vs. formalism
4. Faculty inventions/discoveries and universities'/institutional policies


PrepTest 44 - October 2004
1. Canadian Auto Workers' Legal Services Plan
2. Historiography and Asian settlers of the Pacific Coast
3. Nerve growth factor (NGF) and Rita Levi-Montalcini
4. Modern Movement in architecture


PrepTest 45 - December 2004
1. Natural disaster relief proposals/approaches
2. Hippocratic Oath outdated?
3. Lichen-forming fungi DNA study
4. Aboriginal rights in Canada


PrepTest 46 - June 2005
1. Definition of prosperity. Monetary vs. other considerations.
2. Joy Kogawa's Obasan and rite of passage to become a hero
3. Pronghorn relict behavior, adaptation, fastest land animal
4. Prevention of harm - legal/moral theory


PrepTest 47 - October 2005
1. Downstate campaign, Congress of Racial Equality
2. Chinese Cultural Revolution, Scar Art movement, Revolutionary Realism
3. Family dispute resolution. Mediation programs vs. court adjudication.
4. Pathogen/parasite vs. host


PrepTest 48 - December 2005
1. Aurignacian cave paintings / art
2. Louise Gluck's poetry and gender issues
3. Native Canadians vs. Canadian courts on property rights
4. Embryo polarity, fruit fly, nematode


PrepTest 49 - June 2006
1. Computer-generated courtroom displays
2. Determining tribal origins of African sculptures/art based on style
3. Women doctors in ancient Greece and Rome
4. Maize / corn cultivation


PrepTest 50 - September 2006
1. Mexican-American literature vs. Mexican literature
2. Modern bankruptcy laws
3. Determining national / cultural identity
4. Riddled basins of attraction - John Sommerer and Edward Ott


PrepTest 51 - December 2006
1. Ezekiel Mphahlele, South African writer, mix autobiography/fiction
2. Late heavy bombardment (LHB), craters on the moon
3. Impact of TV in developing nations, cultural imperialism
4. Computer legal reasoning systems


"PrepTest 51.5" - June 2007 - Free Online (PDF)
1. Rita Dove, African American writer, gap between poetry and fiction
2. Music, language, and evolution *
3. The Web, links, copyright law, and intellectual property
4. Irish landscape, history, and preserved pollen grains


PrepTest 52 - September 2007
1. Ousmane Sembene, Senegalese filmmaker, oral tradition, sociopolitical
2. Professional (historical/legal) writing and narrative *
3. Evolutionary game theory, Susan Reichert
4. Philosophical anarchism


PrepTest 53 - December 2007
1. Wing Tek Lum's poetry
2. British common law, Peter Goodrich
3. University research findings as commodities *
4. Cyclamen mites and Typhlodromus mites


PrepTest 54 - June 2008
1. Internet - sovereignty and regulation
2. Drilling muds *
3. Cakewalk, Aida Overton Walker, African American performer
4. Groupthink and group cohesiveness


PrepTest 55 - October 2008
1. Trade secrets and court injunctions
2. Purple loosestrife *
3. Chinese talk-story, Maxine Hong Kingston
4. Dutch tulip market, speculative bubble, Charles Mackay, Peter Garber


PrepTest 56 - December 2008
1. Amos Tutuola, Nigerian writer, folktales, traditional lore
2. Inclusive fitness theory, kin recognition
3. The Roma and definition of national minority, Capotorti *
4. French women and egalitarian educational reform


PrepTest 57 - June 2009
1. FCC vs. United Church of Christ, broadcasting license
2. Humanists vs. scientists, scientific humanism
3. Willa Cather, novel vs. narrative *
4. Fractal geometry, self-similarity


PrepTest 58 - September 2009
1. Ancient textiles, analyzing archaeological remains and texts
2. Parallel computing. Philip Emeagwali, Nigerian-born computer scientist
3. Tangible-object theory of copyright
4. Music, complexity of sounds, and emotions *


PrepTest 59 - December 2009
1. Parallel computing and increased computing capabilities *
2. Importance of teaching statutory law in law school
3. Japanese American sculptor Isamu Noguchi
4. Ultimatum Game. Economics, emotion, and evolution

* = comparative (dual) passages, started in June 2007.

Photo by midatlanticbulldogrescue / CC BY-NC-ND 2.0

Sufficient Assumption Questions | Tips and Categorization

I've talked in the past about how Sufficient Assumption questions are generally based in formal logic. This week, I'm going a bit further with this idea.

I recently analyzed every Sufficient Assumption question from LSAT PrepTests 19-58 (primarily by using the LSAT Logical Reasoning Spreadsheet).

(See these LSAT Logical Reasoning Sufficient Assumption slides from a class I taught for more.)

I found the vast majority of these questions fall into one of the following 6 categories:

1. A restatement of the conclusion / argument

Conclusion / Argument: A --> B

Sufficient Assumption: A --> B

I know it sounds incredibly silly that LSAC would test this, but don't laugh. As you can see below, this is clearly one of the most common patterns for Sufficient Assumption questions.

The correct answer may be worded much differently than the argument/conclusion in the stimulus, even though they cover the same concepts (using double-negatives, synonyms, etc.).

The correct answer may also be worded in more general terms than the argument/conclusion in the stimulus.

Examples (29 questions):
PrepTest 22 (June 1997 LSAT), Section 4, Question 2 - page 138 in 10 More
PrepTest 22 (June 1997 LSAT), Section 4, Question 5 - page 139 in 10 More
PrepTest 22 (June 1997 LSAT), Section 4, Question 13 - page 141 in 10 More
PrepTest 24 (December 1997 LSAT), Section 2, Question 21 - page 200 in 10 More
PrepTest 32 (October 2000 LSAT), Section 1, Question 5 - page 119 in Next 10
PrepTest 33 (December 2000 LSAT), Section 3, Question 21 - page 173 in Next 10
PrepTest 33 (December 2000 LSAT), Section 3, Question 23 - page 174 in Next 10
PrepTest 34 (June 2001 LSAT), Section 2, Question 2 - page 194 in Next 10
PrepTest 35 (October 2001 LSAT), Section 4, Question 19 - page 245 in Next 10
PrepTest 36 (December 2001 LSAT), Section 1, Question 22 - page 260 in Next 10
PrepTest 40 (June 2003 LSAT), Section 1, Question 19
PrepTest 40 (June 2003 LSAT), Section 1, Question 21
PrepTest 41 (October 2003 LSAT), Section 3, Question 22
PrepTest 42 (December 2003 LSAT), Section 2, Question 23
PrepTest 43 (June 2004 LSAT), Section 2, Question 18
PrepTest 43 (June 2004 LSAT), Section 3, Question 16
PrepTest 47 (October 2005 LSAT), Section 1, Question 12
PrepTest 49 (June 2006 LSAT), Section 2, Question 19
PrepTest 49 (June 2006 LSAT), Section 4, Question 18
PrepTest 50 (September 2006 LSAT), Section 4, Question 13
PrepTest 52 (September 2007 LSAT), Section 1, Question 17
PrepTest 52 (September 2007 LSAT), Section 1, Question 20
PrepTest 53 (December 2007 LSAT), Section 1, Question 20
PrepTest 54 (June 2008 LSAT), Section 2, Question 13
PrepTest 55 (October 2008 LSAT), Section 1, Question 4
PrepTest 55 (October 2008 LSAT), Section 3, Question 10
PrepTest 57 (June 2009 LSAT), Section 2, Question 12
PrepTest 57 (June 2009 LSAT), Section 3, Question 24
PrepTest 58 (September 2009 LSAT), Section 1, Question 12


2. The contrapositive of the conclusion / argument

Conclusion / Argument: A --> B

Sufficient Assumption: NOT B --> NOT A

Examples (9 questions):
PrepTest 9 (October 1993 LSAT), Section 2, Question 23 - page 64 in 10 Actual
PrepTest 24 (December 1997 LSAT), Section 2, Question 24 - page 201 in 10 More
PrepTest 34 (June 2001 LSAT), Section 2, Question 10 - page 196 in Next 10
PrepTest 36 (December 2001 LSAT), Section 1, Question 26 - page 261 in Next 10
PrepTest 45 (December 2004 LSAT), Section 1, Question 21
PrepTest 46 (June 2005 LSAT), Section 3, Question 24
PrepTest 48 (December 2005 LSAT), Section 1, Question 25
PrepTest 49 (June 2006 LSAT), Section 2, Question 25
PrepTest 49 (June 2006 LSAT), Section 4, Question 22


3. The sufficient condition of an argument

Evidence: A --> B --> C --> D
Conclusion: D

Sufficient Assumption #1: A
Sufficient Assumption #2: B
Sufficient Assumption #3: C

Examples:
PrepTest 35 (October 2001 LSAT), Section 1, Question 20 - page 225 in Next 10
PrepTest 36 (December 2001), Section 1, Question 18 - page 259 in Next 10


4. The sufficient condition of a argument's contrapositive

Evidence: A --> B --> C --> D
Contrapositive: NOT D --> NOT C --> NOT B --> NOT A
Conclusion: NOT A

Sufficient Assumption #1: NOT D
Sufficient Assumption #2: NOT C
Sufficient Assumption #3: NOT B

Examples:
PrepTest 23 (October 1997 LSAT), Section 3, Question 14 - page 167 in 10 More
PrepTest 44 (October 2004 LSAT), Section 4, Question 26


5. The linkage of two pieces of evidence to form a chain that proves the conclusion true

Evidence #1: A --> B
Evidence #2: C --> D
Conclusion: A --> D

Sufficient Assumption #1: B --> C
Sufficient Assumption #2: NOT C --> NOT B

Examples:
PrepTest 46 (June 2005 LSAT), Section 2, Question 23

PrepTest 48 (December 2005 LSAT), Section 4, Question 21

PrepTest 58 (September 2009 LSAT), Section 1, Question 25

PrepTest 58 (September 2009 LSAT), Section 4, Question 19

6A. The linkage of the conclusion's sufficient condition with the evidence's sufficient condition so the former requires (or falls within) the latter.

(This can only be done after making the necessary conditions of the evidence and conclusion identical.)

Evidence: A --> B
Conclusion: C --> B

Sufficient Assumption #1: C --> A
Sufficient Assumption #2: NOT A --> NOT C

Contrapositively...

6B. The linkage of the evidence's necessary condition with the conclusion's necessary condition so the former requires (or falls within) the latter.

(This can only be done after making the sufficient conditions of the evidence and conclusion identical.)

Evidence: D --> E
Conclusion: D --> F

Sufficient Assumption #1: E --> F
Sufficient Assumption #2: NOT F --> NOT E

(You can often manipulate/rearrange evidence and conclusion for both 6A and 6B above by taking the contrapositive of the evidence, conclusion, or both.)


Examples (37 questions):
PrepTest 19 (June 1996 LSAT), Section 4, Question 11 - page 38 in 10 More
PrepTest 23 (October 1997 LSAT), Section 2, Question 5 - page 157 in 10 More
PrepTest 24 (December 1997 LSAT), Section 3, Question 10 - page 204 in 10 More
PrepTest 24 (December 1997 LSAT), Section 3, Question 19 - page 207 in 10 More
PrepTest 25 (June 1998 LSAT), Section 4, Question 18 - page 245 in 10 More
PrepTest 26 (September 1998 LSAT), Section 3, Question 21 - page 272 - in 10 More
PrepTest 28 (June 1999 LSAT), Section 1, Question 24 - page 328 - in 10 More
PrepTest 31 (June 2000 LSAT), Section 2, Question 10 - page 91 in Next 10
PrepTest 35 (October 2001 LSAT), Section 1, Question 22 - page 226 in Next 10
PrepTest 35 (October 2001 LSAT), Section 4, Question 14 - page 244 in Next 10
PrepTest 36 (December 2001 LSAT), Section 3, Question 12 - page 273 in Next 10
PrepTest 37 (June 2002 LSAT), Section 2, Question 5 - page 297 in Next 10
PrepTest 37 (June 2002 LSAT), Section 4, Question 9 - page 310 in Next 10
PrepTest 37 (June 2002 LSAT), Section 4, Question 20 - page 313 in Next 10
PrepTest 38 (October 2002 LSAT), Section 1, Question 1 - page 322 in Next 10
PrepTest 38 (October 2002 LSAT), Section 4, Question 16 - page 346 in Next 10
PrepTest 40 (June 2003 LSAT), Section 1, Question 8
PrepTest 40 (June 2003 LSAT), Section 3, Question 15
PrepTest 42 (December 2003 LSAT), Section 2, Question 19
PrepTest 44 (October 2004 LSAT), Section 2, Question 13
PrepTest 45 (December 2004 LSAT), Section 4, Question 22
PrepTest 46 (June 2005 LSAT), Section 2, Question 4
PrepTest 47 (October 2005 LSAT), Section 1, Question 9
PrepTest 47 (October 2005 LSAT), Section 3, Question 21
PrepTest 49 (June 2006 LSAT), Section 2, Question 7
PrepTest 50 (September 2006 LSAT), Section 2, Question 22
PrepTest 51 (December 2006 LSAT), Section 1, Question 16
June 2007 LSAT, Section 2, Question 6
PrepTest 52 (September 2007 LSAT), Section 3, Question 15
PrepTest 54 (June 2008 LSAT), Section 2, Question 26
PrepTest 54 (June 2008 LSAT), Section 4, Question 22
PrepTest 55 (October 2008 LSAT), Section 3, Question 21
PrepTest 56 (December 2008 LSAT), Section 3, Question 16
PrepTest 58 (September 2009 LSAT), Section 4, Question 24

***

Some notes on understanding the information above:

I placed the categories above in order from least complex to most complex - not in order of how common they are, of course.

The number of variables in an argument's stimulus / correct answer choice may not perfectly match the number of variables in the category templates I laid-out above (the abstracted versions of the argument types using the letters A, B, C, and D.).

After doing enough of these questions, you'll get to the point where simply by reading the stimulus, you'll often have a sense of which category you're dealing with. If you can do this, you'll often be able to pre-phrase (predict) the correct answer before even looking at the choices.

***

The questions categorized above do not include every single Sufficient Assumption question from PrepTests 19-58. They just include most Sufficient Assumption questions from these exams.

Sufficient Assumption questions not covered above from these exams tended to be less formal-logicky and/or unique in some way. They're still worth looking at, of course.

***

For more on Sufficient Assumption Questions:

Difference Between Necessary & Sufficient Assumption Questions

Logical Reasoning | Sufficient Assumption (Justify) Questions

Photo by 80375783@N00 / CC BY-NC-SA 2.0

Logical Reasoning | Formal Logic Inference Questions

My students know I'm not a fan of diagramming most Logical Reasoning questions. However, some questions just beg to be diagrammed. These questions tend to be formal logic inference questions and sufficient assumption (justify) questions.

In this blog post, I'll cover one Logical Reasoning question that should be easy but gives many test-takers a lot of difficulty when they're first starting Logical Reasoning:

It's PrepTest 30 (December 1999), Section 2, Question 18 (page 59 in Next 10). It's about inspired musical performances, good show, etc.

First sentence:
This part of the stimulus is pretty straightforward and contains clear indicator words (If...then), so we can diagram this as:

IP --> GS


Second sentence:
This one's a bit nasty, as it contains the word "unless." It's a clear example where putting the "unless" translation technique into practice comes in handy.

Take the word "unless" to introduce the necessary condition and negate the other part of the clause to make it the sufficient condition.

"NOT GS" becomes "GS" and is the sufficient condition part of this conditional statement.

"SL" becomes our necessary condition, giving us:

GS --> SL

Instead of writing it down separately (as I just did), I would immediately connect this with the first sentence, giving us:

IP --> GS --> SL


Third sentence:
This one has less obvious indicator words than the first sentence does.

"To be" is the sufficient condition indicator. You may know this more commonly as "in order to be", but this meaning is the same.

"Must" is our necessary condition indicator.

This can be diagrammed as:

SL --> MR

As with the second sentence, instead of writing down the new information separately, I would it immediately connect it with what we already have, giving us a long chain (and its contrapositive):




Attacking the answer choices:
Just check each of the answer choices against the appropriate chain. You'll find that the wrong answer choices are all mistaken negations of one chain and mistaken reversals of the other.

I would not actually diagram or write anything out for any of the answer choices. Instead, I would just read each choice and mentally check it against the choices. It's faster, and you'll find that you don't actually need to write anything out.

Choice A: NOT SL --> NOT IP = CORRECT
Choice B: NOT GS --> NOT MR
Choice C: MR --> IP
Choice D: NOT GS --> NOT MR
Choice E: SL --> IP

Yes, choices B and D are identical - they're just presented differently (D has the word "unless" in it).


What LSAC is likely to ask in a question like this, and why:
The remainder of this blog post is not a description of how I would actually approach this question (or questions of this type). I already covered that above.


I'll number the variables for easy reference:



When asking us what "must be true," LSAC is not likely to ask about any variables that are adjacent to each other (consecutively numbered / touching).

Someone who hadn't connected the sentences into conditional chains would still be able to answer that questions, and LSAC loves it when you're able to connect things.

This means that the correct answer is not likely to be any of the following:

1 requires 2
2 requires 3
3 requires 4
5 requires 6
6 requires 7
7 requires 8

LSAC also isn't likely to ask us anything about the first chain (the variables numbered 1-4).

Asking about the first chain wouldn't require you to have taken the contrapositive. LSAC loves the contrapositive more than milk and cookies. It just makes them so happy.

This means we're likely to deal with the second chain (the contrapositive) - the one with all the negatives.

With the first chain out of the way, our remaining options are:

5 requires 7
6 requires 8
5 requires 8

Sure enough, the answer is 6 requires 8.

Pre-Law Podcast Video Series

I'd like to point everyone toward a pre-law podcast series (complete with accompanying PowerPoints) on Facebook. They're put together by Rebecca Wood, Prelaw Advisor at the University of Nevada, Las Vegas.

Judging by the titles, you can see that they're geared primarily towards beginners, but some of them are relevant to anyone compiling their applications.

There are seven videos in the series. They are:

1. Should I Go To Law School?

2. What Should I Major In?

3. What Do Law Schools Want?

4. What's Up With the LSAT?

5. What's a Personal Statement?

6. How Do I Get Good Letters?

7. Why a Resume and Addenda?

***

You can read plenty of law school admissions advice here on the blog, too.

February 2010 LSAT | Questions and Answers

The February 2010 LSAT is rapidly approaching - only 8 weeks remaining. What would you like to see on the blog between now and then?

Please leave your questions for me (and for each other) in the comments, I'll do my best to answer as many of your questions as possible between now and February 6th.

Quick request: please leave a name rather than posting as "Anonymous." It makes it easier for everyone to respond to specific comments. Thanks!

***

Also see: December 2009 LSAT | Questions and Answers

Photo by lwr / CC BY-NC-SA 2.0

LSAT Logic Game Explanation: Birds in the Forest | Selection

In-Out (Selection) Logic Games are definitely in this year.

The September 2009 LSAT had two of them, and then there was another on the December exam. There goes the popular theory that they wouldn't have an In-Out Game again so soon.

Particularly, LSAC loves In-Out Games where all the rules can be connected (see #1). It's not hard to understand why. They require a solid understanding of conditional reasoning and indicator words.

Despite the fact that In-Out games with similar rules have been administered several times in the past, people still have trouble with them.

I've never diagrammed an In-Out game of this type on the blog - it's time I did.

Birds in the Forest - PrepTest 33, Game 2
(p177 in Next 10)

We know this is an In-Out game because we want "to see which of the following...it contains." In any given scenario, the birds that it contains are "In," and the birds that it does not contain are "Out."

We can connect the rules to form two long chains (which are the contrapositives of each other). We do this by looking for cases where the necessary condition of one rule and the sufficient condition of another are identical. If they are the same, we can link them.

For example, suppose we're given the rules:

If X -> Y

If Y -> Z

In this case, Y is necessary in the first rule and sufficient in the second.

This means we can form the chain X -> Y -> Z.

Now that we have that out of the way, let's go look at the Birds in the Forest game:

First rule:

If H is in, then G is not.

H --> NOT G

I diagram this as:




Contrapositive:

If G is in, then H is not.

G --> NOT H.


Second rule:
If J, M, or both are in, then so is H. The both part is redundant, so we can just say that either one is sufficient to bring about H.

This means that if H is out, then both J and M must have been out.

I immediately connect this rule (and its contrapositive) with what I've written down for the first rule (and its contrapositive).

We now have:


Third rule:
If W is in, then G is in.

Contrapositive:
If G is out, then W must be out.

Connecting this to what we already have, it becomes:


Fourth rule:
If J is out, then S must be in.

Contrapositive:

If S is out, then J must be in.

Connecting these to what we already have, it becomes:




Now we have every rule connected in one big chain - in both the original form of each rule, and its contrapositive. I simply connected each new rule (and its contrapositive) with a previous rule (or its contrapositive) as I read it.

With this big conditional chain, we know that when W is in, both G and S are in, and H, J, and M will be out.

When S is out, both J and H are in, and G and W are out. However, we don't know where M is.

On the chain, proximity/closeness doesn't matter.

Anytime we have a positive variable followed by a negative variable, at least one of those two variables is out. (Maybe both are out.) We don't care whether the negative is immediately after the positive or several variables later.

Anytime we have a negative variable followed by a positive variable, at least one of those two variables is in. (Maybe both are in.) We don't care whether the positive is immediately after the negative or several variables later.

The final question of this game requires a new rule (and its contrapositive) to be added to the diagram. On the diagram, it would look like the following:




Since this is the last question of the game anyway, and assuming you’ve answered all the others, it's okay to modify the main diagram since you won’t be using it for anything else. Whenever a Logic Game requires a new rule to be added, taken away, or substituted for an old rule, it'll be in the last question of the game.


Why the technique in this blog post is better than other techniques:

Some companies recommend listing all the rules in their original form, then writing the contrapositive, then looking for connections. Other methods just fail to adequately represent all the inferences. Either way, they take up a lot of space and time.

Both methods require writing out all the rules and then looking for connections. This leads to a moment of panic when you're not confident whether you've made all your inferences or not. You're never confident that you've done everything.

The method I've laid out above does not require any extra writing, which saves space and time. As long as you can do the contrapositive, you can do this. Just remember that you can only follow an arrow in the direction it points.


A hint for those having trouble:


The chain perfectly represents the relationships between the variables. All the information from the rules already appears on the chain.

A sufficient condition appears to the left of a given arrow, and a necessary condition appears to the right of that arrow.

Just follow the arrows in the direction they're pointing in, and you'll be fine.

The difficulty that many of you have with these conditional chains is you're trying to read them backward, which is not "permitted" in logic. Be careful not to confuse necessary and sufficient conditions.



***

To see this technique demonstrated on another game, check out the diagram I posted for my own In-Out Logic Game.

To see more games like this, check out the first category in 7 Logic Games Repeated on Future PrepTests.


Photo by deniscollette / CC BY-NC-ND 2.0
(Those birds in the photo are grosbeaks, which is what "G" stands for in the game.)

Logic Games Selection | In-Out Diagram Explanation

I've finally written a blog post to explain how I'd diagram my Free LSAT Logic Game | Grouping: Selection / In-Out.

Like the Birds in the Forest Logic Game, this is an In-Out game where the rules can be connected to form long conditional chains.

I designate bills voted "For" as being "In" (positive). I designate the bills voted "Against" as being "Out" (negative).

If you're new to this, or you need a reminder, sufficient is before the arrow, and necessary is after the arrow: Sufficient -> Necessary (see this for more details).


First rule:

G only if NOT E can be diagrammed as



("only if" introduces the necessary condition)



The contrapositive, would be:





Second rule:
(I skip this rule because it mentions variables not mentioned in the first rule. Put a mark next to this rule as a reminder to come back to it.)


Third rule:
This means at least one of E and J must be in, but there's no reason we can't have both in.

This can be diagrammed as:

NOT E -> J

Contrapositive:

NOT J -> E

By connecting this rule (and its contrapositive) to the first rule (and its contrapositive), we get:


and




Second rule:

Now that we have J on our diagram, it's worth taking a look at the second rule because we'll be able to connect the variables in this rule to what we already have on our diagram.

The word "unless" is tricky, but I've recently explained it here.

If you like, you can switch the order of the clauses in this rule in order to think of the rule as "I unless NOT J"

This becomes "NOT I -> NOT J"

Contrapositive:

J -> I

We can immediately connect this rule (and its contrapositive) to what we've already diagrammed, giving us:


and






Fourth rule:

If introduces the sufficient condition, so it should really be thought of as:

H + D -> G

(H and D being in are sufficient to guarantee that G is in.)

Contrapositive:

NOT G -> NOT H or NOT D

On the diagram, it becomes:




Remember that the word "or" is inclusive. This means that if G is out, at least one of H and D will be out, but perhaps both of them will be out.

For the "or," some people like to use a dotted-line arrow rather than a solid line and writing the word "or." With a dotted-line arrow, this rule would look like:



Either way is fine - as long as you know what it means.


Question 7's rule:

Question 7 adds a new rule: F --> NOT J

Take the contrapositive: J --> NOT F

Add both to the diagram, and you get:




***

With the rules correctly diagrammed in these chains, you should be able to get through the game's questions on your own. Most of the difficulty is in setting up the game and forming the chains.

I talk about how to read this type of diagram in my explanation of the LSAC-written Birds in the Forest Logic Game.

Photo by wallyg / CC BY-NC-ND 2.0

LSAT Logic in...Conservapedia

Andy Schafly, creator of Conservapedia (wiki) was interviewed on The Colbert Report Tuesday night.

2:52 in the video below is where the LSAT-relevant action is:

Schafly: Isaac Newton, for example, credited his insights to the work he did translating the Bible - not just reading the Bible.

Colbert: He came up with gravity when a Bible fell out of a tree!

Schafly: Not only did Newton credit his work in translating the Bible, he said that everyone else he knew who translated the Bible also had terrific other insights, so it's a marvelous activity.

See any major flaws?

The Colbert Report	Mon - Thurs 11:30pm / 10:30c
Andy Schlafly
www.colbertnation.com

***

Also see LSAT Logic in the Colbert Report | Marijuana Legalization.

Princeton Review LSAT Logic Games Workout - Exposed

In the LSAT FAQ, I discuss some reasons why you shouldn't use books containing fake (non-LSAC-written) LSAT questions.

However, there's one reason I didn't mention. Depending on the source, these "fake questions" might actually expose you to real LSAT questions from recent exams.

How is this possible if the questions are fake?

The Princeton Review's new LSAT Logic Games Workout book fails to mention that, in a way, it does use real LSAT questions. In fact, it implies that it doesn't at the end of the second paragraph on page 1.

However, this book contains games that appear to be slightly-altered versions of several real LSAT Logic Games from recent PrepTests.


I see three major possibilities here:

1. This is just a big coincidence.

2. Earlier this decade, LSAC test-writers used a time machine, traveled forward in time to 2009, saw this book's Logic Games, loved them, and decided to alter them for use in real exams over the next few years. (Reminds me of Biff and the sports almanac in Back to the Future II.)

3. The authors took real LSAT Logic Games written by LSAC and changed the Logic Games' topics and variables. In many cases, they also changed the presentation and order of the rules, as well as the order in which the questions are presented. In some cases, they added a question of their own to the game.

The 3rd possibility appears to be the most likely, so I'll go forward on the assumption that the 3rd possibility is the correct one.


Why is this bad?

Consider the following:

Joe Bloggs, your average uninformed LSAT-taker (who doesn't read my blog, or he would've used these books instead):

1. sees an LSAT Logic Game for the first time and cries

2. works through the LSAT Logic Games Workout

3. does a few recent exams under timed conditions and does much better on the Logic Games than expected

4. merrily strolls off to his test center for the real thing, thinking his improvement was a result of using the Workout book

5. does significantly worse on the real thing than expected


Little does he know that the most recent exams he took basically contained the very same Logic Games as the ones in the Workout book.

For this reason, Joe's practice test scores were inflated. This gave him a false sense of confidence. As a result, he wasn't able to make an informed decision about whether he was ready to take the exam. Had he known that he wasn't as strong in Logic Games as he'd thought, he would've been able to think about whether he needed to cancel his LSAT score, postpone the test, or simply be absent.


Poor Joe...we can't really blame him for not realizing he simply did the same Logic Games twice - first in the Workout book, and then in the actual PrepTests.


After all:

1. Some time had probably passed between doing the Workout book and the full-lengths.

2. Under the pressure of a timed practice exam, he probably didn't have the leisure to have feelings of deja vu. ("Hey, this Logic Game setup looks familiar...")

3. The variables (letters) had been changed. The Workout version of a given Logic Game may have contained the variables A-G, while the PrepTest version may have contained a game with the variables H through N.

4. The Workout version's topics had been changed from the actual PrepTest's LG topics.

5. The order in which the rules were presented had been changed.

6. The order in which the questions were presented had been changed.

7. Some games had an additional question in the Workout version.

8. In general, the wording had been slightly changed.

9. Like most people, Joe probably likes to attribute any good performance to his own intelligence rather than outside factors - like being exposed to the material already.

10. As I said at the beginning of this post, the book's introduction suggests the questions contained within the book are not real (LSAC-written) LSAT questions.

I don't know who should be more embarrassed:

---The Princeton Review - for presenting a bunch of altered LSAC-written games as their own, rather than licensing unaltered LSAT Logic Games from LSAC

or

---Me - for being able to identify the origin of each "fake game" just by looking at its rules.


Luckily, the folks at The Princeton Review were kind enough to allow Google to scan and display part of their Logic Games Workout book.

***

Below, I've linked to the 8 Logic Games from the Workout book available for viewing in Google Books. Along with each game, I've included the actual PrepTest # and Game # so those of you interested in the details can compare the two.

Of course, don't look at any game you plan to complete in the future as part of a full-length practice test. We don't want your practice test score to be skewed.


---

Some Logic Games in the LG Workout Book based on real LSAT Logic Games:

1. Solar Panels (page 14 in Workout)

Compare to:
PrepTest 42 (December 2003), Game 2 - Loading dock - fuel, grain, livestock, machinery, produce, and textiles


2. Mother's Day Bouquets (page 19 in Workout)

Compare to:
PrepTest 43 (June 2004), Game 1 - Civic parade - firefighters, gymnasts, jugglers, musicians, puppeteers, and veterans


3. Blog Rater (page 36 in Workout)

Compare to:
PrepTest 51 (December 2006), Game 2 - Six hotel suites - most expensive to least - F, G, H, J, K, and L


4. Great Bank Bailout (page 40 in Workout)

Compare to:
PrepTest 52 (September 2007), Game 1 - Water treatment plant - G, H, I, K, L, N, O, and P


5. Lounge Crawl (page 50 in Workout)

Compare to:
PrepTest 52 (September 2007), Game 4 - Bread truck / delivery - Figueroa, Ginsberg, Harris, Kanzaki, Leacock, and Malpighi


6. Mixed Nuts (page 59 in Workout)

Compare to:
PrepTest 46 (June 2005), Game 4 - Secret committee - French, Ghauri, Hsia, Irving, Magnus, and Pinsky


7. Six Blind Mice (page 64 in Workout)

Compare to:
PrepTest 52 (September 2007), Game 2 - Field trip to Museum of Natural History - Juana, Kyle, Lucita, Salim, Thanh, Veronica, and Margoles, O'Connell, and Podorski


8. Coalition of Conservationists (page 69 in Workout)

Compare to:
PrepTest 45 (December 2004), Game 4 - Nations X, Y, and Z - Export Alliance - oranges, rice, soybeans, tea, and wheat.


(The LSAC versions of games numbered 2, 3, 7, and 8 above contain only 5 questions each. The Princeton Review added a 6th question to each of these games.)

***

As you can see, these games are primarily from exams test-takers are likely to use for full-length timed practice.

Moral of the story: Don't use The Princeton Review's Logic Games Workout book. Its typos (described in detail in its reviews on Amazon) clearly aren't the only problem.

Any LSAT book you use should include real LSAT questions (and tell you which exams each question came from.)

Necessary Assumption Questions, Negation Test, and Must Be True Qs

Last week, I discussed the difference between necessary assumption questions and sufficient assumption questions.

I've already covered some strategies for sufficient assumption questions, but I haven't yet written about necessary assumption questions.

In this blog post, I discuss a common, and effective, strategy for approaching these questions.

I also talk about shortcomings in the way prep companies often teach test-takers to think about necessary assumption questions.

Finally, I give some examples of necessary assumption questions and explain some frequent patterns in each.

A Common and Effective Strategy for Necessary Assumption Questions: The "Negation" / "Denial" test

As the name implies, this "test" requires you to negate each of the answer choices. The correct answer choice, when negated, renders the argument invalid. The argument cannot be valid if the necessary assumption is not true. After all, the necessary assumption is, in fact, necessary for the argument to work

I agree with the consensus that this is a good way to approach necessary assumption questions.


How does this work in practice?

Ask yourself as you read each answer choice, does this *need* to be true for the evidence to require the conclusion?

Well, if it weren't true, what would happen? Would the argument be able to coexist with the negated answer choice?

If it would not be able to, then it is the necessary assumption, so it's our answer.


Again, the correct answer choice needs to be true in order for the argument to work. As the common question stems suggest (examples of those in Difference Between Necessary and Sufficient Assumption Questions), the argument depends upon the assumption being true, requires that it is true, and assumes that it is true.



A Quick Note on Negating Answer Choices

Make sure to translate the answer choice into its logical opposite, not its polar opposite.

Example:

The polar opposite of the statement "All people are standing" is "All people are not standing." In English, that means "No people are standing." It's the other extreme. We don't want this.

The logical opposite of the statement "All people are standing" would be, "It is not the case that all people are standing." In English, that means "Not all people are standing" or "Some people are not standing."



Necessary Assumption Questions Do Not Bring in New Information

Many categorization systems correctly place Must Be True questions under the umbrella of Inference questions (those asking for information we already know to be true based on the stimulus).

However, they typically categorize Necessary Assumption questions differently, placing them with  Strengthen and Sufficient Assumption questions. This is a mistake. Necessary Assumptions don't simply help the argument, and they certainly don't bring new information to the table, as Strengthen questions and Sufficient Assumption questions do.

Necessary Assumptions are things we already know to be true based upon the stimulus.



Necessary Assumption Questions are Really Must Be True Questions in Disguise

In all the LSAT materials I've looked at (and I've looked at quite a few), the authors place Necessary Assumption questions in a separate category from Must Be True questions.

In fact, the negation test described above works precisely because Necessary Assumption questions are Must Be True questions in disguise. I proved it to you above when I plucked key words from Necessary Assumption question stems: "depends upon," "requires," and "assumes." Something required to be true is something that must be true.

We could easily take any Necessary Assumption question, remove its question stem, and replace it with a Must Be True question stem, such as the following:

If all of the statements above are true, which one of the following must also be true?

Nothing would change. The Necessary Assumption question's credited response would answer this question as well because the necessary assumption must be true if we assume the argument is valid.



Why Does the LSAT Even Have Necessary Assumption Questions?

Why not just ask Must Be True questions all the time? Why does LSAC even bother with these? What makes them different from Must Be True questions?

-Must Be True questions often involve connecting a few different pieces of information from the stimulus. (See PrepTest 29, Section 4, Question 23, p42 in Next 10, or see PrepTest 33, Section 3, Question 8 - p170 in Next 10.)

-They often involve formal logic and are simply fact sets, rather than arguments (PrepTest 30, Section 2, Question 18 - p59 in Next 10, or see PrepTest 32, Section 1, Question 7 - p120 in Next 10).

In short, they require you to make various types of connections between different pieces of information in the stimulus.

Necessary Assumption questions, on the other hand, ask for a more specific type of information that must be true. They ask for something that must be true in order for the argument itself to be valid.



Examples:

By this point, you're probably foaming at the mouth for some examples of necessary assumption questions, so I've some picked out for you:

Common Necessary Assumption Question Pattern #1
PrepTest 30 (December 1999), Section 2, Questions 15 and 22 (pages 58 and 60 in Next 10, respectively)

In each of these questions, the stimulus' argument makes the claim only one thing needs to be true for something to occur. For each of these questions, the correct answer dismisses a potential problem that might otherwise prevent the conclusion from logically following.

Common Necessary Assumption Question Pattern #2
PrepTest 37 (June 2002), Section 4, Questions 15 and 19 (pages 312 and 313 in Next 10, respectively)

In each of these questions, the stimulus' argument mentions something new in the conclusion that was never mentioned in the evidence. They also mention something in the evidence that was never mentioned in the conclusion. As such, the new thing in the conclusion needs to be made relevant in some way for its presence in the conclusion to be justified. If it were not relevant to the evidence in any way, the argument would not be valid.


***

P.S. To be clear, I think of Necessary Assumption questions as a specific kind of must be true question - they are asking for something slightly different (an unstated / implicit premise). It's a different question type for a reason. But I certainly wouldn't think of them as being a type of strengthen question.

There's still a difference in terms of approach (which is likely why they're separate question-types).
To elaborate, what I'm saying is - what if you took that entire series of statements, i.e. the entire text of the stimulus, as given? Wouldn't all underlying necessary assumptions need to be true?

For Necessary Assumption Qs (and Must Be True Qs), gravitate more towards moderate language - it's more likely to be correct (supported by the stimulus) than more extreme language would be.


Photo by nathangibbs / CC BY-NC-SA 2.0