Threats to Reliability

Error, which produces threats to reliability, can be introduced by:

1. The researcher or measurement instrument: For example, if you’re measuring time to do a task, when do you start and stop the stopwatch? How quickly can you react to starting and stopping the stopwatch? What if multiple researchers are using a stopwatch?

2. The participant: For instance, a participant’s mood may affect how they respond to a survey or the time of day may affect their weight on a scale (note that their weight fluctuates throughout the day but that affects the reliability of their weight, not the reliability of the scale!)

3. The environment: For example, baking at different altitudes requires different oven temperatures and baking times.