to avoid the disapproval of the researcher. A second cause for this type of bias was proposed by Lee Cronbach, when he argued that it is likely due to a problem in the cognitive processes of the participant, instead of the motivation to please the researcher. He argues that it may be due to biases in memory where an individual recalls information that supports endorsement of the statement, and ignores contradicting information. Researchers have several methods to try and reduce this form of bias. Primarily, they attempt to make balanced response sets in a given measure, meaning that there are a balanced number of positively and negatively worded questions. This means that if a researcher was hoping to examine a certain trait with a given questionnaire, half of the questions would have a "yes" response to identify the trait, and the other half would have a "no" response to identify the trait. Nay-saying is the opposite form of this bias. It occurs when a participant always chooses to deny or not endorse any statements in a survey or measure. This has a similar effect of invalidating any kinds of endorsements that participants may make over the course of the experiment. Courtesy bias Courtesy bias is a type of response bias that occurs when some individuals tend to not fully state their unhappiness with a service or product as an attempt to be polite or courteous toward the questioner. It is a common bias in qualitative research methodology. In a study on disrespect and abuse during facility based childbirth, courtesy bias was found to be one of the causes of potential underreporting of those behaviors at hospitals and clinics. Evidence has been found that some cultures are especially prone to the courtesy bias, leading respondents to say what they believe the questioner wants to hear. This bias has been found in Asian and in Hispanic cultures. Courtesy bias has been found to be a similar term referring to people in East Asia, who frequently tend to exhibit acquiescence bias. As with most data collection, courtesy bias has been found to be a concern from the phone survey respondents. Attempts were made to create a good interview environment in order to minimize courtesy bias. An emphasis is needed that both positive and negative experiences must be important to showcase to enhance learning and minimize the bias as much as possible. Demand characteristics