Use of Statistics in Psychology
By Ahmed Mujtaba Owaisi
Statistics is the branch of mathematics which deals with the organization, analysis and interpretation of a group of numbers. Use of statistics in Psychology is essential for conducting any research. The term Statistics is derived from a Latin word “Status” which means government or a state. Initially statistics was used by the states to collect data about their public including population, income, and to impose taxation etc. Statistics is essential for research in social sciences because it consists of various techniques to organize, summarize, and interpret the data. In simple words, statistics enables us to get information from the data. According to Agresti and Finlay (1997) statistics is a methodology used by a researcher to collect, interpret and draw conclusions from a collected data.
How statistics help a Researcher:
Statistics is essential for conducting a research in the field of psychology and social sciences. It helps the researcher in various ways as follows
- The most important part of a study is to select a sample size which represent the population of the study, statistics is used to determine the size of the sample.
- What kind of data is required for the study
- Which techniques will be used to analyze the data
- How to draw conclusion from the analyzed data
- What is the significance of the findings of the study and how much uncertainty is there in the findings?
In this way statistics enables a researcher to design, describe, analyze and make inferences from his research.
There are various functions of statistics. It helps the researcher to present his findings in an easy to understand way. For example, when a researcher say that 200 people of a city suffer from some specific kind of allergy, it is not clear for the reader to draw conclusion from it. Further it can be stated that 200 people from a city with a population of 200000 suffer from the illness. It makes better sense about the findings for a reader. Further with the use of statistics the researcher report that 0.1 percent of the population of the city suffer from the illness. It better explain the findings in a clear manner. Meanwhile statistics enables the researcher to make comparisons and to draw conclusions from the data with the use of various statistical techniques. He can see difference in terms of gender, education, socioeconomic status and so on with the use of statistics. Furthermore, statistics enables the researcher to represent complex information and a large number of data in a simple way by using diagrams, graphs and tables. As the term statistics was first used by the states, it helps the government to make policies to implement for the benefit of their public.
Where Statistics Work:
In order to make statistics work properly the researcher should consider the following points.
- Statistics only work with numbers.
Statistics is a branch of mathematics which deals with numbers only. It does not work with qualitative information (in words). In order to make it work properly we convert the information into numbers. For example Beck Depression Inventory (BDI) is a common inventory in psychology used for the assessment of depression. It consists of a four point Likert scale (ranging from 0-3), in research we use the numbers to draw conclusions by using statistics.
- Various external factors can affect the findings of the study. In this regard it is important for the researcher to minimize or exclude the external factors which may affect the findings of the study. For example, we want to study the grades of students in specific class and we should focus on various factors including the role of teacher, class and examination hall environment, and various other factors.
- There are also chances of two major types of errors known as type-I and type-II error which on behalf of the researcher affect the findings of a study in a negative way. In this regard the researcher should be careful in the interpretation of the findings and also exclude any chance of biasness on his behalf.
- The use of statistics in any study is pre-planned on the basis of synopsis or initial framework of the study which is determined by different factors including literature review. For example, a researcher studying the phenomenon of depression will initially include different demographic variables in his study including gender, age, education, family type, grades etc.
- The process of data collection in statistics is also predetermined according to the needs of the study. Various methods are available to determine sample size which better represent the population.
- Statistics is useful for related variables only. It does not work with the variables which do not have any relationship at all. In simple words, you can see the correlation between depression and academic performance, difference in the level of depression among male and female population but in case of variables which are not associated, you cannot use statistics. For instance, statistics will not work when you will try to study IQ and internet surfing duration which both are not related with each other.
Use of Statistics in Daily Life:
There are a number of uses of statistics in our daily life as well as statistics in psychology. For example, it is used by researchers to conduct various studies in order to examine various variables. Statistics is also useful because it enables the researcher to specify the required information and sample size in order to waste his time and energy.
We all use various weather forecasting applications like accuweather. These applications provide us prediction about the weather of today and upcoming days with a high level of accuracy. This forecast about weather is also available because of the use of statistics in which they analyze the weather in previous days and current day which enables them to predict the weather in upcoming days.
When any medicine is made to treat any illness its effectiveness is first determined with the use of statistics. Pharmacists make drug does and effectiveness graphs by using statistics to determine the level of effectiveness of the drug to treat the illness as well as to determine the proper dose for the human beings.
Statistics is also used by media for various purposes. For example, before elections newspapers and TV channels collect data from the public to predict the results of any election by showing the percentage of public which support different political parties.
Governments also use statistics for various purposes to collect data about their public. For example, census is used by the governments to collect data about the population of their citizens. In current scenario the whole world is fighting with the dangerous disease known as COVID-19. The data of people affected by the disease as well as the prediction of the level of danger of the disease in upcoming days is the best example of the use of statistics.
In the field of Psychology, we use various types of scales, inventories and psychological tests to examine various factors like depression, anxiety, procrastination, IQ, and personality factors etc. The reliability and validity of these tests is also determined with the use of statistics.
Furthermore, statistics is also used by business markets for various purposes. When any company launches any product in the market, it determines the response of the customers with the use of statistics. It also enables them to make further improvements in their products by considering the likelihood of their customers. Statistics is also used by police, hospitals, schools, banks and various other sectors.
Meanwhile there are also some limitations of the use of statistics. These limitations include:
- Statistics work only with quantitative data which consists of numbers. In order to make statistics work with qualitative data we need to convert the data into numbers.
- Statistics is a branch of mathematics but still it has some limitations. It provides us with an estimation not with accurate results. Furthermore, it deals with social sciences which deals with human beings. We cannot predict the behavior of human beings with 100% accuracy but it provides the findings with maximum accuracy.
- Statistics work only with a sample of population while it does not work with an individual. In this regard when studying any variable of psychology, the use of statistics will enable us to examine the variable in the public as a whole not among individuals.
- Sometimes the findings of any statistical results may lead the readers to some confusing information. For example, if any newspaper or media report that in any specific institution 33% of the administrative staff is suffering from depression. This finding may be very big at initial stage for the reader that a high majority of the administrative staff is suffering from depression. But the administrative staff of that specific institution consists of only three members and only one of the staff is suffering from depression it will provide us with the clear image of the findings.
Use of Statistics in Psychology
The use statistics in psychology is to conduct research in the field. We study various variables with the help of statistics. Most of educational programs in psychology have thesis as an essential requirement of the degree and all these thesis have some statistical analysis which are done with the use of statistics. We determine the sample size, measure the correlation between different variables, and assess the role of gender and other factors with the use of statistics. Further statistics enables us to measure the effect of one or more independent variables on some dependent variables through regression analysis. Mediation and moderation analysis are also conducted with the use of statistics. Psychologists develop scales and tests to measure different factors with the use of statistics. In short statistics is essential to conduct research in almost every field of social sciences including psychology, economics, education, media studies, political science, commerce, and so on.