Problem: Dr Splash is conducting a laboratory experiment to test whether older adults detect emotions as quickly as younger people. He has two groups of participants, older and younger ones. This is his IV. He tests them by comparing how quickly they press a button to say that they have recognized the emotion on a face of a screen. This is the DV. Each participant sits at the same distance from the screen. This is one aspect of the standardisation of the procedure. In a pilot study, Dr Splash had shown the participants pictures and used a stopwatch to time their reactions himself, but he found he was not very consistent in his ability to stop timing exactly when the participant responded. He therefore changed to the computerized system to improve reliability. The pictures of faces included both younger and older people to ensure it was a valid test.
- Name and explain the experimental design being used in this study.
- Suggest why the use of faces of a range of ages would have improved validity.