Role of Statistical Inference in Psychology

When a researcher wants to understand if a particular therapeutic technique will work on people, will they apply it to everyone on this planet? Will it be extremely time-consuming and tedious to do so? Similarly, a market researcher who wants to understand if a particular marketing strategy works or not does not practically apply the strategy to all markets to observe the technique's effects. How do we ensure a method's workings or impact without applying it to every target audience? The field of statistics has made it relatively easy for humans to achieve the task. Statistics is a science that handles the collection and interpretation of numerical data. This branch of mathematics deals with the collection of quantifiable data. Why do statistics do this? The simple answer is to arrive at conclusions to understand a larger population.

Types of Statistics

Statistics can be divided into following two types

What do we understand by Statistical Inference

Simply by observation, we cannot be certain of anything. For instance, if you observe that coffee impacts human alertness just by observing ten people, you cannot conclude that caffeine raises alertness. It is important to have scientific measures in place. An essential aim of inference is to make conclusions about phenomena that are generally not observed with high levels of certainty. The inference task is challenging because it requires a sample for concluding, and the primary aim is to analyze the larger population based on the representative sample.

Over here, the population can be defined as the individuals, events, or objects we desire to study or test our ideas upon. For instance, if you wish to study the impact of coffee on alertness, the population could be school-going students or employees who need higher levels of concentration. Since it is practically impossible to study every student, we draw a sample population from our desired population. For example, we can sample 200 school-going students studying in grade 11.

Defining Statistical Inferences

We can understand statistical inference in terms of analyzing the outcome and coming to conclusions with the provided data that is a randomly selected sample. The applications of inferential statistics include the following

  • Hypothesis testing

  • Confidence intervals.

In summary, inferential statistics is a method where we arrive at conclusions about a larger population based on a randomly selected sample. When we want to understand the relationship between two variables, inferential statistics can be very helpful. For example, consider the relationship between coffee and alertness. Therefore, it helps us understand the relationship between dependent and independent variables. By using the method of inferential statistics, it becomes easier to understand the impact of various variables on the human population or how the population relates to certain variables.

If we want to arrive at a better and more reliable conclusion, it is important to keep in mind the following factors while selecting a sample

  • Random selection of sample − This means that the sample is selected so that every individual in the desired population has an equal and fair chance of being selected for the study.

  • Non-biased − The samples are selected fairly, and no bias is reflected at any stage.

  • Size − The size of the sample is manageable. A very small sample has no statistical significance, even if it yields the expected result, and it cannot be generalized to a larger population.

What are the steps involved in Inferential Statistics?

Many steps are involved in arriving at statistical inferences. Here is the process


It is important to have a theory in mind to generalize it to a larger population. We cannot begin with anything in mind, and it is important to have some notion or idea to begin with. For example, we have observed that when someone consumes caffeine, they feel fresher and more focused.

Establishing a hypothesis

This is an important step. A hypothesis is a tentative statement related to our theory, which helps to give some direction to our study. In inferential statistics, there can be a null or alternative hypothesis.

Defining the variables

Our variables can mean different things to different researchers. For instance, focus or alertness can have different definitions or levels. In any study, it is important to give operational definitions to the variables so that the study is objective.

Sample population

This step involves selecting a sample population for the study. The sample population must be selected carefully and randomly. It is important to note that this sample is chosen from the population to which the results should be applied.

Testing the hypothesis

Once the data is collected using appropriate methods, the hypothesis should be tested. Inferential statistics uses the following methods to test the hypothesis

Analyzing the result

The main aim of inferential statistics is to analyze the data to apply it to a larger population. This stage involves coming to conclusions and understanding if the results could be applied to a larger population. If not, the study can be revised with new aims and hypotheses.

Why is it important to study Inferential Statistics?

How does the study of inferential statistics help us in our daily lives? Inferential statistics can help us understand large amounts of data, and we can come to reliable conclusions using this method. Studying every individual in a population is practically impossible, and this statistical method helps us scrutinize the data sufficiently. In addition to this, it helps predict future outcomes in several domains. Here are some fields where inferential statistics contribute a lot

  • Market research − Several domains, such as consumer behavior, consumer usage, market trends, and stock market research, use inferential statistics to establish useful patterns for predicting future outcomes.

  • Artificial intelligence − Search engines use inferential statistics to generate traffic to a website. Several companies use data analytics to sell ads.

  • Forensic sciences and law enforcement − These departments use data from the past to predict criminal behavior or deviant activities.

  • Financial planning − Economies use data from previous years for financial planning, resource allocation, or policy making.


Statistics, a branch of mathematics, is very useful in understanding numerical data. There are two main branches of statistics. Descriptive and inferential statistics The latter branch deals with understanding and analyzing the data to come to logical conclusions. Therefore, statistical inference is a method of understanding a theory and forming conclusions about a "population" with the help of a sample population. Since there is a certain degree of certainty in our observation and study, inferential statistics helps to generalize results from this sample population to the larger population.