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The survey has bias. (a) Determine the type of bias. (b) Suggest a remedy. The village of Oak Lawn wishes to conduct a study regarding the income level of households within the village. The village manager selects 10 homes in the southwest corner of the village and sends an interviewer to the homes to determine household income.

Short Answer

Expert verified
The bias is 'Sampling Bias'. Use random sampling across the village to avoid it.

Step by step solution

01

Identify the Bias Type

Evaluate the method of selecting the sample. In this case, the village manager selects homes only in the southwest corner of the village.
02

Determine Bias

Since the sample is taken from only a specific geographical area, it may not represent the whole village accurately. This type of bias is called 'Sampling Bias'.
03

Suggest a Remedy

To avoid sampling bias, use a method that ensures all households in the village have an equal chance of being selected. A better approach would be to use random sampling across the entire village.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Survey Methodology
In order to gather reliable data, it's essential to follow a structured approach known as survey methodology. This involves various steps to ensure the data collected is accurate and representative of the population. For instance, when the village of Oak Lawn wanted to understand the income levels of its households, they needed to carefully plan their survey. The steps in survey methodology typically include: identifying the research question, choosing the target population, selecting a sampling method, designing the survey, collecting data, and then analyzing the results.
One major aspect is choosing the right sampling method. Incorrect methodology can lead to errors or biases, making the data unreliable. In the Oak Lawn example, sticking to homes in just one part of the village was not methodologically sound. It didn't account for the variability in income levels across different areas. Proper survey methodology ensures inclusivity and accurate representation across various demographics and regions.
Random Sampling
Random sampling is a technique used to ensure each member of a population has an equal chance of being selected. This is crucial for obtaining unbiased results. In the context of the Oak Lawn study, random sampling across the entire village would provide a more accurate picture of household incomes.
Random sampling methods include simple random sampling, stratified sampling, and cluster sampling. For instance:
  • Simple Random Sampling: Every household has an equal chance of being selected through random generation.
  • Stratified Sampling: The village could be divided into sections or 'strata', each representing different income levels, and random samples can be taken from each stratum.
  • Cluster Sampling: Randomly selecting entire sections of the village, ensuring they represent the entire population.
This approach reduces the likelihood of certain areas being over- or under-represented, thus avoiding sampling bias.
Bias Remedies
Bias in surveys can significantly skew results, making them unreliable. Hence, remedies for bias are essential for obtaining valid data.
  • Expand Geographic Range: Instead of selecting homes from a small area, expand the range to cover the entire village. This ensures diverse income levels and demographics are included.
  • Increase Sample Size: Having a larger sample size can help to average out anomalies and provide a better representation of the population.
  • Random Sampling: As discussed, using random sampling techniques helps to give every household an equal opportunity to be part of the survey, reducing the risk of bias.
In the case of Oak Lawn, ensuring that the sample includes households from all corners of the village can help provide a more accurate and fair representation of the village's income distribution. Therefore, with these remedies, the survey results will be more credible and useful for decision-making.

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