Question

A) Threats to the validity of an experiment: Confounding variables/ confounds

Explain each of these three confounds, and the measures that are used to prevent them. The text does not identify #2 and #3 as confounds, but they are.

Confounding variable / Preventive measure

1. Participant bias / Blind the participants

2. Experimenter bias /Double-blind study

3. Participant characteristics /Random assignment

Answer 1

1. Participant bias results from the tendency of participants to second-guess what the researcher is after, and change their answers or behaviors in different ways, depending on the experiment or environment. In order to reduce the impact of this bias experiments can blind the participant. In this scenario, information about the study is masked or hidden from the participant, to reduce or eliminate bias, until after a trial outcome is known.

2. Experimenter bias occurs when researchers, either consciously or unconsciously, perform the research in a manner to influence the results and portray a certain outcome. In a double-blind study, neither the participants nor the experimenters know who is receiving a particular treatment. This reduces the chances of subjective feelings and biases influencing how the subjects respond or how the data is collected.

3. Participant characteristics can function as extraneous variables that impact how he or she responds and convolute the IV-DV relationship. These factors can include background differences, mood, anxiety, intelligence, awareness and other characteristics that are unique to each person. Random assignment can ensure that these individual differences are distributed more or less equally across different groups in the experiment.