discuss the difference between descriptive statistics and inferential statistics. In your post, explain three measures used in descriptive statistics and three tests used in inferential statistics.
Expert Answer
Descriptive Statistics Definition
The descriptive statistics is the type of statistical analysis which helps to describes about the data in some meaningful way. The statistics is used to describe quantitatively about the important features of the data or information. The descriptive statistics gives the summaries of the given sample as well as the observations done. These summaries or descriptions can either be graphical or quantitative.
For Example: In soccer, the individual performance of each player is said to be the descriptive statistics.
However, descriptive statistics does not reach at conclusions beyond the given data or hypothesis made by the researcher. It is just a simple way of describing the data.
Generally, the kinds of measure that are used with descriptive statistics are:
1) Measures of Central Tendency:
The measure of central tendency describes the data which lies in the center of a given frequency distribution. The main measures of central tendency are mean and median and mode.
2) Measures of Spread:
The measure of spread describes the how the scores are spread over the whole distribution. Standard deviation, variance, quartiles, range, absolute deviation are included in the measures of spread.
3) Graphical Representation:
There are several different types of graphs that are used to describe about the statistical data. These graphs are histogram, bar graph, box and whisker plot, line graph, scatter plot, ogive, pie chart and many more.
Inferential Statistics Definition
Inferential statistics is the type of statistics which deals with making conclusions. It inferences about the predictions for the population. It also analyses the sample. Basically, the inferential statistics is the procedure of drawing predictions and conclusions about the given data which is subjected to the random variations. Inferential statistics includes detection and prediction of observational and sampling errors. This type of statistics is being utilized in order to make estimates and test the hypotheses using given data.
The inferential statistics may be defined as the answer of the question “what is needed to be done next”. This provides an information about the further surveys and experiments. Inferential statistics enables the researcher to draw conclusions before the implementation of some particular organizational policy.
There are two major divisions of inferential statistics:
1) Confidence Interval:
The confidence interval is represented in the form of an interval that provides a range for the parameter of given population.
2) Hypothesis Test:
Hypothesis tests are also known as tests of significance which tests some claim for the population by analyzing sample.
Basis for Comparison | Descriptive Statistics | Inferential Statistics |
---|---|---|
Meaning | Descriptive Statistics is that branch of statistics which is concerned with describing the population under study. | Inferential Statistics is a type of statistics, that focuses on drawing conclusions about the population, on the basis of sample analysis and observation. |
What it does? | Organize, analyze and present data in a meaningful way. | Compares, test and predicts data. |
Form of final Result | Charts, Graphs and Tables | Probability |
Usage | To describe a situation. | To explain the chances of occurrence of an event. |
Function | It explains the data, which is already known, to summarize sample. | It attempts to reach the conclusion to learn about the population, that extends beyond the data available. |
Examples of Descriptive Statistics:
i) Estimation of number of students (boys and girls separately) in a school.
ii) Population of particular county or city.
iii) Frequency of the variables.
iv) Estimation of number of damaged or cavity teeth by a dentist.
Examples of Inferential Statistics:
i) Average marks obtained by all the students.
ii) Grades or percentile of the scores.
iii) Average score in cricket.
iv) Prediction by a dentist about the teeth that are susceptible to have cavity or damage in future.