Sample Size: A Fundamental Guide for Accurate Research

Aug. 03, 2023

Sample Size: A Fundamental Guide for Accurate Research

An accurate research representation begins with a basic element, the sample size or the number of participants. Drawing the map of market research surveys or customer surveys starts with the sampling group. 
Imagine you want to know what people in a city think about a new product. It's impossible to ask every single person, so we pick a representative sample of individuals from different areas and backgrounds. This group will give us valuable insights without having to survey everyone. Selecting the right sample size is essential. If it's too small, we might miss important viewpoints. But if it's too big, we could end up with redundant information. By finding the right balance, we ensure the data is reliable and relevant.
In short, sample size is the backbone of accurate research. By choosing the right group of participants, we gain valuable insights into the larger population's views and preferences. With this knowledge, businesses can make well-informed decisions to achieve success.

How Sample Size Can Influence Results?

The precision and adaptability of study results are directly influenced by the sample size. A limited survey sample may provide biased or inconclusive findings since it does not fully reflect the population. On the other hand, a large sample offers a more accurate depiction of the population, lowering sampling inaccuracy and increasing the possibility of drawing valid inferences.
Imagine a company wants to know whether their new product appeals to customers. If they only survey 300 people, they might get skewed results, like 200 out of 300 participants preferring the product. But if they ask 800 people, the findings will likely be more reliable.
When we draw conclusions from data, we're trying to make inferences about an entire population based on a smaller subset, known as the sample. A small sample size can lead to misleading conclusions, while a larger one tends to be more accurate.

What You Need to Know to Calculate Survey Sample Size?

To determine the proper size for market research surveys or business surveys, the following criteria must be taken into account:

Population Size: The total number of participants in the intended population that the survey attempts to reflect.

Confidence Level: A measure of trustworthiness in the survey's findings, sometimes given as a percentage.

Margin of Error: This is the permitted range of variation or degree of doubt in the survey findings, usually given as a percentage.

Expected Proportion: a calculation of the anticipated number of people in the population who display a particular feature or reaction (for binary outcomes).

How Can You Calculate Sample Size?

When no previous data are provided, the following formula can potentially be used to calculate sample size for a basic random sample:


 (n) The necessary sample size.
 "(Z)" refers to the Z-score that corresponds to the required degree of confidence. The Z-score for a 95% confidence interval is around 1.96.
 "(p)" denotes the estimated percentage of the population that has the desired feature.
\(E\) The intended margin of error is given as a percentage.

Is There an Easier Way to Calculate Sample Size?

The aforementioned method is rather simple to calculate the sample size. However, when the study involves many variables, multistage sampling, or stratified sampling, it starts to get more difficult. But we have made such lengthy calculations easy for you. You’ll have the sample size for your market research survey in just a few clicks. When you will use our sample size calculator you will need to remember the criteria that are to be used. Moreover, there are algorithms used in the calculation process but they would not make any error. Our tool would give you the exact sampling size. 

Different Types of Surveys and Their Sample Size Considerations

NPS Survey (Net Promoter Score)

The Net Promoter Score (NPS) survey is frequently employed to gauge client happiness and loyalty. On a scale of 0 to 10, participants are asked to assess how likely they are to suggest a product or service. Respondents are categorized into three groups to calculate the NPS: Promoters (scoring 9–10), Passives (scoring 7-8), and Detractors (scoring 0-6).

A high survey sample size i.e., 30% of the total customer base is preferred for NPS surveys. It enables greater classification of the participants into the aforementioned categories. A greater survey sample size also guarantees that the NPS score is a better reflection of the total customer base, offering important insights about customer retention.

Employee Survey

Employee contentment, participation, and average work experience are measured via employee surveys. The size of the corporation will determine the sample size for an employee survey, although in general, businesses with a bigger workforce would need a larger sample.

Employee surveys often involve stratified sampling, in which various departments or employment levels are treated as independent strata, to guarantee accurate findings. This method helps in ensuring that the sample accurately reflects the variety of viewpoints prevalent throughout the corporation.

Brand Survey

Brand awareness and market stance are evaluated via brand surveys. The market presence of the brand and the study's goals will determine the right number of participants for a brand survey.
Researchers can strive for a larger sample size if the brand's consumer base is modest to improve the reliability of the results. Alternatively, a lower number of participants can be enough if the brand has a substantial market presence.

Customer Survey

Customer surveys are carried out to gauge client satisfaction and individual tastes while collecting input on certain goods or services. The number of clients the business serves and the required degree of accuracy should be taken into consideration when choosing the sample size for a customer survey.
To make certain the findings are statistically meaningful, a large sample size could be necessary for companies with countless clients. However, a lower sample size could be sufficient for smaller companies to ensure acceptable illustration.

Bottom Line

A crucial component of every research project or survey is the sample size. The accuracy, dependability, and universality of the findings to the wider population are all guaranteed by a well-determined and adequately sized sample. When calculating the number of participants or subjects, researchers must take into account many variables, including the overall population size, confidence level, margin of error, and expected percentage.

Market research services can play a vital role in helping researchers determine the appropriate sample size for their studies and surveys. As a leading provider of market research solutions, QDegrees offers a wide range of expertise and resources that researchers can leverage to ensure the accuracy and reliability of their findings.

One of the key challenges in research is calculating the ideal sample size that represents the target population accurately. This is where QDegrees' expertise comes into play. QDegrees utilizes advanced research methodologies and cutting-edge technologies to streamline the process of sample size calculation. Whether researchers are conducting NPS surveys or employee surveys, we can assist them in determining the optimal sample size to yield meaningful insights.