Which of the Following Is an Example of an "Experimenter-Expectancy

Multiple Choice

Which of the following is an example of an "experimenter-expectancy effect?"

A) participants in a study are nicebehave differently for the attractive experimenter than for the less attractive experimenter
B) a researcher finds that his participants did not behave as he expected them to, so he changes his statement of his hypothesis when he writes up his results
C) participants come to experiments with preconceived notions of what they are supposed to do, and perform based on those notions rather than on what they are asked to do.
D) the experimenter "expects" females to experience more difficulty on a math task so the experimenter unintentionally behaves in ways that undermine the performance of females on the math task