A researcher assigns participants to either an experimental or a placebo group without informing them. The researcher’s students who test the participants are also unaware of the participants’ assigned group. In this scenario, the experiment has used a

A researcher measured the performance of two groups of employees. One group received low monetary incentives first and was later given high monetary incentives. The other group was given high monetary incentives first and was later given low monetary incentives. At each stage, the employees’ performance was measured. This scenario exemplifies a(n)

Phillipe, a researcher, examined the effect of lighting on learning. Randomly selected participants were asked to learn the same chapter using either a 100-watt or a 125-watt bulb. He found no difference between the learning capacities of the two groups. The nonsignificant results may have occurred because of

If the two groups involved in an experiment are not equivalent,

While Daisuke is performing a cognitive task, a researcher uses a physiological measure that scans various areas of Daisuki’s brain. In this case, the researcher is most likely using a(n)

How can expectancy effects be reduced?

Kalim wants to study the effectiveness of a new teaching method. He includes two teachers of a class in the experiment. One teacher uses the new method of teaching, and the other teacher uses the old method. At the end of the semester, he finds that students who were taught in the new way had higher grades than students taught in the old way. What is the confounding variable?

An employment agency wants to examine the employment rate in a city. The agency’s researcher divides the population into the following subgroups: age, gender, graduates, nongraduates, and discipline of graduation and then randomly selects sample members from each of these subgroups. This is an example of

A researcher designs an experiment in which the following variables are manipulated: temperature (low or high), illumination level (low or high), and time of testing (day or night). For a repeated measures design, how many participants would the researcher require in order to have 10 participants per condition?

In a survey, participants were asked if they agree with the statement “I like spending my free time with other people.” They were also asked if they agree with the statement “I enjoy being alone during my free time.” This type of questioning helps in identifying