Which of the following would be considered a source of error in an experiment?

a. laboratory mice are similar but not identical to each other.
b. a student makes a mistake when measuring volume.
c. the hypothesis was unrelated to the research question.
d. temperature readings are made late in the day, when everyone is tired and eager to go home.

D. Temperature readings are made late in the day, when everyone is tired and eager to go home.

Errors are what makes your measurement invalid and unreliable. There are two types of error which is called the systematic error and the random error. Each error has different sources. Words that were mentioned –invalid and unreliable are very important key aspects to determine that your measure is truly accurate and consistent. Some would recommend using the mean method, doing three trials in measuring and getting their mean, in response to this problem.