Four major sources of measurement error.

Four major error sources:

• The Respondent
• The Situation
• The Measurer
• The Data Collection Instrument

The Respondent

When it comes to a face to face interview the researcher can encounter  participants that don't want to give a strong negative or positive opinion.  Also, the participants may have no knowledge of the subject with no intentions of revealing that to the researcher, which can cause the data collected to be full with guesses or assumptions.

The Situation

In a face to face interview the situation factor can affect the data in different ways. First, if someone is present during the interview this person can interrupt, distract or just by being there can change the participants answers. Second, if the participant is afraid that the interview responses are not going to be kept anonymous the may be reluctant to give the right answer. Finally, participants in face to face interviews give less elaborate answers compare to the home interviews.

The Measurer

 The interviewer can change responses by paraphrasing, rewording or reordering the questions, which can cause a major change in the responses by the participants. Also, not concentrating by checking the wrong response or not recording the complete responses can distort the findings.

The Instrument

If the researcher instruments to conduct the interview can cause distortion in two major ways. First, it can cause confusion to the participant by using complex words beyond the participant comprehension. The use of mechanical defect tools, not waiting or giving enough space for response, and poor printing can cause the final data findings. Second, poor selection from the universe of content items. The interviewer can create a bad survey by not including more broad questions about the entire subject or company that they are trying to investigate. Even when the general issue or subject are studied, the questions may not cover enough aspects of each area of concern.