# Introduction to Statistics for Psychologists

## What is Statistics?

Statistics is a branch of applied mathematics dealing with data

1. collection,
2. organization,
3. analysis,
4. interpretation and
5. presentation

Statistics is used especially in the areas where there’s a bit of uncertainty involved. You have various tools to estimate the ‘uncertainty’ (dispersion) and derive conclusions from it (summarise). We can also use the structured observation to make estimates or predictions.

For example, saying that there will be 10AM tomorrow is certain, but if I say all of you will stay awake through this statistics lecture – is very uncertain. It is uncertain because different unknow factors are involved here – maybe, one of us does not like statistics at all! Or maybe some of us could not sleep well last night.

Statistics helps us make ‘better’ sense out of such ‘uncertainties’. There are tools with which I can measure the effectiveness of the lectures, summarise it to your HOD. It also has helpful tools that will help me to make lectures more interesting in future and estimate how many people may find it boring tomorrow.

Descriptive statistics has tools to summarise data. For example, suppose you were studying the effectiveness of online teaching-learning process through a questionnaire: you use tools in descriptive statistics to summarise the responses you get from participants. We can use graphs like bar diagram, histogram, pie chart etc. to make our summaries more visually attractive.

Inferential statistics make predictions. For example, consider the predictions before elections. They don’t conduct a nation-wide survey with every voter: they select a smaller group of 1000-2000 and use the input from them to estimate the results.

### How is Statistics Relevant to a Psychology Students?

Psychology is the study of mind and behaviour. Statistics is one of the most central tools used by psychologists, mainly because there is a lot of uncertainty involved when you study the human mind and behaviour.

Suppose you were studying the impulsiveness in making decisions in a certain locality – we know that there are many factors involved – how big can the locality you are studying be? Since impulsiveness is dependent on mood of a person, how will be factor that into our results? How are we going to measure how impulsive a person is? Will they give a right answer if you simply ask them, “Are you impulsive?” That’s where statistical tools you learn here comes into picture. Knowledge of such tools helps you make those decisions.

Related Lecture Video: Video 1