Compare explanations before choosing a cause · LSAT Reasoning

How to use this workshop

Work one case at a time before reading its explanation. First identify what is granted, then state exactly what the advocate wants you to accept. A conclusion question asks for an argumentative role; a flaw question asks whether the connection succeeds; a weakening question asks how new information changes its support. These are related but different tasks. Your answer to one should not become a shortcut around reading the next question. Keep the premises fixed when evaluating a proposed new finding, and watch for choices that merely restate the conclusion.

Library Volunteers

A library emailed its newsletter subscribers about Sunday opening. Of the 120 subscribers who replied, 92 favored Sunday opening. The advocate infers: Most town residents favor Sunday opening.

The point to examine is the connection, not whether the topic sounds familiar. It generalizes from a self-selected group of newsletter readers to all town residents.

Contrast the effects of two possible findings. A representative town survey found that only one third favored Sunday opening. This challenges the stated inference. By contrast, A representative random sample of all town residents also mostly favored Sunday opening. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.

River Filters

Factories installed new river filters in March. Fish counts downstream rose during the following summer. The advocate infers: The filters caused the increase in fish counts.

The point to examine is the connection, not whether the topic sounds familiar. It treats an outcome following an intervention as establishing that the intervention caused it.

Contrast the effects of two possible findings. An unusually strong upstream spawning season increased fish counts equally in rivers without new filters. This challenges the stated inference. By contrast, Tests showed that the new filters removed a pollutant known to harm fish eggs. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.

Park Cycling

Cyclists using a park loop report fewer back problems than adults who do not cycle. The cyclists also report enjoying their exercise. The advocate infers: Taking up cycling will reduce back problems in the adults who currently do not cycle.

The point to examine is the connection, not whether the topic sounds familiar. It overlooks the possibility that existing back problems affect who chooses to cycle.

Contrast the effects of two possible findings. Many adults avoid cycling because their preexisting back conditions make cycling uncomfortable. This challenges the stated inference. By contrast, In a randomized trial, suitable cycling reduced back problems relative to a noncycling control. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.

Business Survivors

A magazine interviews founders of businesses that have lasted at least twenty years. Most interviewed founders say they avoided outside investors. The advocate infers: Avoiding outside investors makes new businesses more likely to survive twenty years.

The point to examine is the connection, not whether the topic sounds familiar. It considers survivors without comparing the investor choices of businesses that failed.

Contrast the effects of two possible findings. Failed businesses were even more likely than survivors to have avoided outside investors. This challenges the stated inference. By contrast, A representative study of all new businesses finds higher long-term survival among those without outside investors. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.

Tutor Selection

Students who choose an optional tutoring program improve more than students who do not choose it. Participants also tend to complete more homework before joining. The advocate infers: The tutoring program itself explains the entire difference in improvement.

The point to examine is the connection, not whether the topic sounds familiar. It fails to separate the program's effect from preexisting differences between volunteers and nonparticipants.

Contrast the effects of two possible findings. The same improvement gap was present before the tutoring began. This challenges the stated inference. By contrast, Randomly assigned students with equivalent prior performance improve more when assigned to tutoring. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.

Bad Month Rebound

A warehouse introduced coaching immediately after its worst safety month in ten years. The next month had fewer accidents. The advocate infers: The coaching caused the full reduction in accidents.

The point to examine is the connection, not whether the topic sounds familiar. It overlooks the possibility that an unusually poor result would be followed by a more typical result without intervention.

Contrast the effects of two possible findings. Comparable warehouses with equally unusual bad months improved just as much without coaching. This challenges the stated inference. By contrast, Randomly assigned warehouses given the coaching improved more than comparable controls. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.

Rescue Prevention

Hospital admissions for heat illness fell after shaded shelters were installed. At the same time, the city changed admission rules so mild cases were treated without admission. The advocate infers: The shelters account for the entire fall in hospital admissions.

The point to examine is the connection, not whether the topic sounds familiar. It overlooks a concurrent change that can affect the measured outcome.

Contrast the effects of two possible findings. The admission-rule change explains nearly all of the decline even in areas without shelters. This challenges the stated inference. By contrast, Emergency-call data unaffected by admission rules show an additional decline specifically near shelters. This would support the conclusion or address the gap. Neither finding should be silently treated as one of the original premises.

Now close the explanation and describe the reasoning in a different context. Preserve the same distinction rather than copying a key phrase. If the original claim says must or entirely, ask whether the evidence supports that strength. A limited challenge need not show that every part of a proposal is false.