HOW DETERMINE SAMPLE SIZE
Anietie Imo, acpa
Introduction
Determining the appropriate sample size for your survey or study involves considering several factors to ensure that the results are statistically meaningful and representative of the population you’re studying. Here’s a general approach to determining sample size:
1. Define Your Population:
Clearly define the population you want to study. In your case, it would be public-private enterprises that are affected by trade restrictions and their investment decisions.
2. Decide on the Desired Level of Confidence:
Typically, researchers aim for a confidence level of 95%, which means that if you were to conduct the study multiple times, you would expect the results to fall within the margin of error 95% of the time.
3. Determine the Margin of Error:
The margin of error is the maximum acceptable difference between your sample estimate and the true population parameter. A smaller margin of error requires a larger sample size. The margin of error is usually expressed as a percentage of the sample proportion.
4. Estimate the Variability:
You need an estimate of the variability or the expected proportion of the population that possesses the characteristic you’re interested in. In your case, it could be the proportion of public-private enterprises that are affected by trade restrictions and experience changes in their investment volume.
5. Use a Sample Size Calculator:
There are online sample size calculators available that can help you determine the required sample size based on the factors mentioned above. You can use calculators specific to your study design, such as those for proportion estimation since you’re dealing with Likert scale responses.
6. Pilot Testing:
Before conducting the full survey, consider conducting a pilot test with a small sample to identify any issues with the questionnaire or the survey process. This can help you refine the survey and make improvements before collecting data from your target sample.
7. Account for Non-Response and Attrition:
Keep in mind that not everyone you approach will participate, and some participants may drop out before completing the survey. To account for this, you might need to recruit a slightly larger sample.
8. Ethical Considerations:
Ensure that your sample size is appropriate to avoid over-surveying or putting undue burden on participants.
9. Seek Expert Guidance:
If you’re unsure about the statistical aspects of determining sample size, consulting with a statistician or someone experienced in survey design can be beneficial.
Remember that the specific requirements for your study may vary based on the research methodology, the level of precision you need, and the characteristics of your target population.