A researcher is conducting an experiment to test the effects of a new study technique. They first select 60 participants from a list of all undergraduate students at a university. After the participants are recruited, the researcher uses a coin flip to determine whether each participant will use the new technique or the traditional technique. Which of the following best describes the difference between these two procedures?

A cognitive psychologist recruits 60 volunteers for a memory study. To ensure the experimental groups are comparable, she uses a random number generator to determine whether each volunteer will complete the memory task in a noisy room or a quiet room. This specific procedure of allocating volunteers into the two different environments is an example of random sampling.

A researcher aims to conduct an experiment that both represents the general population and allows for a clear determination of cause and effect between variables. Arrange the following methodological steps in the logical sequence required to satisfy both of these goals.

A student is designing a psychology experiment to test whether listening to classical music improves short-term memory performance. The student wants the findings to generalize to the full undergraduate population at their university AND to be able to conclude that any observed difference in memory scores was caused by the music. Which of the following study protocols best achieves both goals?

In psychological research, random assignment is the procedure used to select a representative sample of participants from a larger population.

A researcher conducts a study on the effect of background music on concentration. They use a computer program to select a representative group of participants from a university's entire enrollment list. After selecting them, the researcher allows the students to sign up for either the 'music' group or the 'silence' group based on their personal study habits. When evaluating the validity of the researcher's claim that 'music causes better concentration,' a peer reviewer would argue that the use of random sampling successfully addressed external validity, but the failure to use _____ makes it impossible to rule out preexisting differences between the students in each group as the true cause of the results.

Match each term or concept on the left to the description that best fits it in the context of research design.

Match each researcher's action to the correct concept it demonstrates in the context of research design.

Dr. Gao recruits 80 student volunteers to test a new learning app. She assigns the first 40 students who sign up to the experimental group and the remaining 40 to the control group. Because she did not use a random process to distribute the participants after they were recruited, Dr. Gao's study lacks random _____ , leaving the comparability of the two groups compromised.

Evaluate the chronological progression of an experimental study that attempts to maximize both representativeness and internal comparability. Order the steps from first to last.