Case Study

Analyze this research scenario. In light of the findings from Ibolya, Brake, and Voss (2004), diagnose the threat to internal validity created by this experimenter-participant assignment. Explain how the experimenter's sex acts as an extraneous variable and how it may have artificially masked or altered the true effects of the independent variable.

Case context: A research group is studying the effect of visual imagery on pain tolerance. They recruit 60 participants (30 male, 30 female) who immerse their hands in icy water. The testing team consists of a male researcher who runs all trials for the male participants, and a female researcher who runs all trials for the female participants. The researchers conclude that their visual imagery intervention resulted in moderate, uniform pain tolerance improvements across all participants.

Question: Analyze this research scenario. In light of the findings from Ibolya, Brake, and Voss (2004), diagnose the threat to internal validity created by this experimenter-participant assignment. Explain how the experimenter's sex acts as an extraneous variable and how it may have artificially masked or altered the true effects of the independent variable.

Sample answer: In this study, the assignment of same-sex experimenters (male experimenter with male participants; female experimenter with female participants) creates a systematic threat to internal validity. According to Ibolya, Brake, and Voss (2004), participants tolerate pain longer in cross-sex pairings (e.g., male tested by female) and less in same-sex pairings. By using only same-sex pairings, the researchers likely suppressed overall pain tolerance scores across both groups. This suppression acts as an extraneous variable that may have masked the true strength of the visual imagery intervention, preventing an accurate assessment of its effectiveness.

Key points:

  • Analyze the experimenter-participant pairings (same-sex only).
  • Connect the setup to Ibolya et al. (2004) findings where same-sex pairings show lower pain tolerance.
  • Diagnose the threat to internal validity (extraneous variable suppressing scores).
  • Explain that this suppression could mask or confound the true effect of the independent variable (visual imagery).

Rubric: Students must analyze the case using Ibolya et al.'s finding that same-sex pairings result in lower pain tolerance compared to cross-sex pairings. They must explain how matching same-sex pairs across all conditions systematically reduces the observed pain tolerance scores, potentially masking the true effect of the visual imagery intervention (the independent variable), thereby compromising internal validity.

0

1

Updated 2026-05-27

Contributors are:

Who are from:

Tags

KPU

Research Methods in Psychology - 4th American Edition @ KPU

Related