How does the LSAT define a "strengthening effect"?

The correct answer is based on the understanding of how strengthening effects operate within the context of logical reasoning. A "strengthening effect" occurs when additional evidence supports an argument, enhancing its credibility or persuasive power. Essentially, it adds weight to the reasoning, making the conclusion more acceptable or convincing to the audience.

By presenting new information that aligns with the argument or bolsters its claims, the argument becomes more robust. This is particularly important in logical reasoning, as the aim is to evaluate the strength of arguments. Therefore, identifying supporting evidence that reinforces an argument is key to understanding how effective it is in persuading or informing an audience.

The other options mischaracterize what a strengthening effect entails. Weakening an argument or making it less credible is contrary to the definition of a strengthening effect. Simplifying arguments is also not synonymous with strengthening them, as simplicity does not inherently add credibility or support to the claims being made.