Branches of Statistics
1. Descriptive statistics – The branch of statistics that
summarize and describe certain statistical parameters [Mean, SD, SE, Variance
etc.] of data.
2. Inferential statistics – The branch of statistics that used to
draw conclusions and to make inferences that are based on the data.
Salient Features
1. Through analysis statistics provide meaning to the
measurement.
2. Statistics also explore or establishes relationship between
data and its application.
3. Statistics help in precising & making accurate
description.
4. The statistics is a logical process that provide a way of thinking,
vocabulary and
language.
5. Statistics make data ‘talk’.
6. Statistics deals with both type of data i.e., enumeration data
and metric data.
Uses of Statistics
The statistics is employed to
achieve the following tasks in psychological sciences: -
1. Analyzing the causal factors behind a phenomenon.
2. Summarizing or describing large amount of data.
3. Making comparisons between individuals and/or groups.
4. To explore or establish the relationship between measured
variables.
5. Making prediction about the future events.
6. Statistics aids in informed decision making.
Attention!
The statistics can be used or
misused, so prevent the misuse of statistics the following points must be kept
in mind: -
1. The inferences arrived at by statistics need careful
interpretation. Incorrect interpretations are worse than wasted efforts
(Guilford and Fruchter, 1978).
2. Before application of statistical technique, the researcher
must make sure that the data meet the assumptions of the intended statistical
technique.
3. Refrain from making general remarks based on statistical
inferences.
Description of terms
1. Enumeration data
– The data that yields frequencies as a result of counting.
2. Metric data or Measurements – The data that has been obtained as result of
measurements.
3. Mean, Median and Mode
– A single number that provides scientific description about the position of an
individual, group, sample or a product on a continuum in context of others.
4. Standard Deviation (SD) – Statistical indicator of the amount of
variability in a set of individuals
or observations.
5. Coefficient of Correlation – The degree and direction (positive or negative)
of closeness of relationship between
two sets of measures of the same group of individuals or observations.
6. Sample –
A group of people representing the population of interest selected
for experiment.
7. Sampling Statistics –
It tells the degree of representativeness of the population from the sample has
been drawn.
8. Standard Error
– It is an index number that leads us to conclusion concerning how far the
statistic derived from sample probability differs from the value
we would obtain if we had measured
an entire population.
9. Population
– A well-defined group of people or observations.
Some common Notations
1. 𝑿 ̅ – Mean of observed data or
frequency distribution.
2. s – Standard deviation of observed data or frequency
distribution.
3. s² – Variance of observed data or frequency distribution
4. µ - Mean of probability distribution or expected value or
theoretical distribution.
5. σ – Standard deviation of probability distribution.
6. σ² - Variance of probability distribution.
7. ∑ - Summation
References:
Guilford, J. P. and Fruchter, B. (1978). Fundamental
Statistics in Psychology and Education, 6th ed. Tokyo: McGraw-Hill.
https://todayinsci.com/M/Mahalanobis_Prasanta/MahalanobisPrasanta-Quotations.htm.
Garrett, H. E. (2014). Statistics in Psychology and
Education. New Delhi: Pragon International.
Levin, J. & Fox, J. A.
(2006). Elementary Statistics. New Delhi: Pearson.
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