Question

Explain how a psychologist might select a sample for a survey.

Short answer

A psychologist might select a sample for a survey by first defining the relevant population, choosing an appropriate sampling technique, determining a suitable sample size, and then conducting the actual selection according to the chosen technique.

Step-by-step solution

Define the Population

The researcher should clearly define the population of interest. This could be a specific group of people, such as students, parents, sufferers of a certain psychological disorder, etc. This group should be relevant to the research question and objectives.

Choose a Sampling Technique

There are various methods of sampling available, such as random sampling, stratified sampling, cluster sampling, etc. The appropriate technique depends on the nature of the population, the objectives of the study, and the resources available. For example, if the population is quite homogeneous and the researcher has access to a list of all members, simple random sampling could be a suitable choice.

Determine Sample Size

The sample size should be large enough to accurately reflect the population, but not so large as to waste resources. There are statistical tools and conventions to help determine an appropriate sample size for various study designs. Usually, the larger the population size, the smaller the proportion of the population the sample needs to represent. However, depending on the sampling technique and researcher objectives, sample size can vary.

Select the Sample

Depending on the sampling technique, the actual selection of the sample could involve randomly drawing names from a hat, selecting every 10th person on a list, or using a random number generator. For some techniques, it may involve more complex procedures, such as dividing the population into subgroups (strata) and sampling separately from each.

Key concepts

Population Definition

Before diving into any survey research, defining the population is a crucial first step. In psychological studies, a population refers to the entire group of individuals the researcher is interested in studying. This could be a group such as teenagers experiencing anxiety, adults living in urban areas, or any other specific group that aligns with the research objectives.
A properly defined population ensures that the findings of the study are relevant and applicable. The population must be precisely determined so the sample can be appropriately chosen to represent it. A clear definition helps in minimizing biases and in creating a robust research framework.
By narrowing down exactly who is in the population, researchers can tailor their survey tools and strategies more effectively towards the group's characteristics and needs. Precision at this stage helps pave the way for a successful survey, ensuring that all subsequent steps are aligned with the study's goals.

Random Sampling

Once the population is defined, selecting how to gather data from this group involves choosing a sampling technique. One popular method is random sampling. This approach is ideal when the researcher can access a complete list of the population, as it provides each individual with an equal opportunity to be selected.
Random sampling involves different methods such as drawing names from a hat or using a computer-generated list. The randomness ensures that the sample is unbiased, representing the population's diversity without the influence of personal selection preferences.
By employing random sampling, researchers can increase the reliability of the survey results. It minimizes the skewing of data, thereby providing a more valid reflection of the population. This method is foundational in psychological research, aiming to mitigate selection bias and enhance the credibility of the findings.

Sample Size Determination

Determining the sample size is a balancing act between accuracy and resource management. A correct sample size mirrors the population adequately, giving a representative snapshot without overextending efforts. Several statistical tools exist to guide researchers in deciding the optimal sample size based on study design and objectives.
The size of the population typically guides the proportion needed in the sample; generally, larger populations require smaller percentage samples. Yet, the method of sampling and specific research goals can significantly influence sample size decisions.
Researchers aim for a sample size that supports both statistical significance and practical resource use, ensuring the study is both scientifically sound and economically feasible. Careful consideration at this stage helps avoid errors in data interpretation and enhances the validity of conclusions drawn from the research findings.

Psychological Survey Research

Psychological survey research is a widely used methodology to explore human behaviors, thoughts, and feelings. It involves collecting data through questionnaires or interviews to understand psychological phenomena within the defined population.
This approach allows researchers to gather information on a large scale, analyzing trends and correlations within significant samples. Surveys can be applied in various areas, from understanding consumer behavior to evaluating mental health interventions.
For the research to be effective, surveys should be carefully designed to suit the population and research objectives. This includes considering how questions are phrased and the method of delivery, whether online, face-to-face, or via telephone.
Through psychological survey research, insights can be gained that are pivotal in shaping interventions, policies, and understanding human psychology. By following structured sampling methods and ensuring robust survey designs, meaningful and applicable conclusions can be drawn.