Descriptive Statistics
It is used to analyze and represent the data that have been previously
collected. It includes frequency counts, ranges (high and low scores or
values), means, modes, median scores, and standard deviations
Central
Tendency
Central
tendency is a statistical measure to determine a single score that defines the
center of distribution. Covers: Mean, median, mode
Frequency
distribution
Frequency distribution is an organized
tabulation of the number of individuals located in each category on the scale
of measurement. Graps used: Histogram, Frequency polygon, Bar diagram etc.
Mean
The mean, is commonly known as arithmetic
average, is computed by adding all the scores in the distribution and dividing
by the number of scores. Formula ยต = SX/N
Median
The median is the score that divides a
distribution exactly in half.
When N is an odd number : 3, 5, 8, 10, 11;
Then its median will be = Median = 8.
When the N is an even number: 3, 3, 4, 5, 7,
8; Median = 4 + 5 / 2 = 9 /2 = 4.5
Mode
The final measure of central tendency is
called mode. In a frequency distribution the mode is the score or category that
has the greatest frequency. A set of scores = X = 5, 5, 4, 4, 4, 4, 4, 3, 3, 3,
2, 2, 1, 1. Now in this data 4 is the mode because it is has the
greatest frequency
Normal
distribution
A normal distribution is an arrangement of a
data set in which most values cluster in the middle of the range and the rest
tapper off symmetrically toward either extreme. Its graph called bell curve as
it has flattered shape.
Types of
sampling
Deliberate sampling-it is a
sampling technique where researcher purposively or deliberately selects certain
units of the universe to form a sample that would represent the universe
Simple random sampling-it
is kind of sampling in which sample group members are selected in a random
manner
Systematic random sampling-it is a
sampling technique where a random starting point is selected and then every Kth
member of the population is selected
Stratified random sampling- sampling
technique in which a population is divided into subgroups called ‘strata’ and
then sample is randomly selected from each ‘stratum’
Quota sampling- sampling
technique where sample group members are selected based on specific criteria
Cluster sampling-Cluster
sampling involves grouping the population and then selecting the groups or the
clusters rather than individual elements for inclusion in the sample
Multistage sampling- referred
as two stage sampling. In the first stage a sample of area is chosen then in
the second stage a sample of respondents within the areas is selected
Sequential sampling- sampling
technique wherein researcher picks a single or group of subjects in a given
time interval, conducts his study, analyzes the result and picks another group
of subjects if needed and so on. It is a complex sample design where the
ultimate size of the sample is not fixed
