Question

A study of about \(n=1000\) individuals in the United States during September \(21-22,2001\) revealed that \(43 \%\) of the respondents indicated that they were less willing to fly following the events of September \(11,2001 .^{19}\) a. Is this an observational study or a designed experiment? b. What problems might or could have occurred because of the sensitive nature of the subject? What kinds of biases might have occurred?

Short answer

Identify potential problems and biases in this study related to the sensitive nature of the subject. Answer: The given study is an observational study. Potential problems and biases in this study include response bias, nonresponse bias, sampling bias, and timing bias, which may have impacted the accuracy of the results.

Step-by-step solution

a. Observational study or designed experiment?

To answer this question, let's first understand the difference between an observational study and a designed experiment. In an observational study, researchers observe and measure the variables of interest without influencing or controlling them in any way. In a designed experiment, researchers impose a specific treatment or intervention on the subjects and then measure the outcomes. In this study, researchers collected data about people's willingness to fly after the events of September 11, 2001, without influencing or controlling their opinions or behaviors. Therefore, this study is an observational study.

b. Potential problems and biases

Due to the sensitive nature of the subject, there might be several issues and biases that could impact the results of the study. These include: 1. Response bias: Respondents might not have provided accurate answers to the questions posed by the researchers, due to the emotional impact of the events of September 11 or as a result of social desirability. People might want to appear more patriotic or pro-aviation industry during such times, resulting in biased responses. 2. Nonresponse bias: Some individuals might not have responded to the survey because they were too emotionally distressed or wished to avoid discussing the events. This might exclude a certain section of the population from the study, leading to nonrepresentative results. 3. Sampling bias: The sample of 1000 individuals might not be representative of the entire United States population. The extent to which this sample is representative of the wider population will depend on how the individuals were selected for participation in the study. If the sample was not selected randomly, it might introduce sampling bias. 4. Timing bias: The survey was conducted shortly after the events of September 11, and the emotional state of people might have been impacted by the recent happenings. The results might have been different if the survey was conducted at a different time.

Key concepts

Response Bias

Response bias occurs when participants of a study provide answers that are not accurate or truthful. Various factors can cause this to happen:

• Emotional Influence: After major events like September 11, people's emotions might heavily influence their responses. Those emotionally affected might provide answers that align more with their feelings than their actual intentions.
• Social Desirability: People often want to present themselves in a socially acceptable way. Right after such a significant national event, respondents might claim they would fly to appear brave or patriotic, even if they have private concerns.

This bias skews the results, as it doesn't genuinely capture respondents' true feelings or intentions. Overestimating or underestimating concerns can lead to incorrect conclusions about people's behavior regarding flying.

Nonresponse Bias

Nonresponse bias happens when a portion of the target survey group does not participate in the study. This can occur for several reasons, especially in sensitive topics.

• Emotional Distress: After traumatic events, some individuals might find participating in surveys about such events too distressing to handle, leading them to avoid responding altogether.
• Lack of Interest or Avoidance: Some might not see the value in taking part, or they might actively avoid discussions about topics they find uncomfortable.

When a significant number do not respond, it can create a skewed representation of public opinion. The study might miss out the perspectives of those who were too affected or unwilling to participate, creating an incomplete picture.

Sampling Bias

Sampling bias refers to the issues that arise when the population chosen for the study is not representative of the entire population. In this context, the sampling process should aim to reflect the diverse demographic composition of the United States.

• Selection Process: If the 1000 individuals were not randomly selected, or if they were selected from groups more likely to have similar views, such as specific geographic locations or demographics, sampling bias could occur.
• Geographic Concentration: Heavy concentration in particular areas, like cities close to major airports, may result in opinions that differ from rural areas.

Ensuring a representative sample is essential to reliably showcase the opinions of the entire population. Otherwise, the findings may not accurately reflect the broader sentiment towards flying post-September 11.

Timing Bias

Timing bias involves the influence that the timing of a survey can have on the results. Events' proximity can significantly affect how participants respond.

• Recency of Events: Conducting the study shortly after September 11 means that emotions were still raw, likely impacting how respondents felt about flying.
• Emotional Reactions: Immediate emotional reactions can lead to short-term decisions that might not reflect long-term feelings or behaviors.

Conducting the survey weeks or months later might yield different levels of willingness to fly, as people's immediate fears lessen and logic takes precedence. Timing bias can thus lead to temporary, rather than enduring, perceptions in the study results.