Explanation : Regression to the mean occurs whenever
a non-random sample is selected from a
population and two imperfectly correlated
variables are measured, such as two
consecutive blood pressure measurements.
The less correlated the two variables, the
larger the effect of regression to the mean.
Also, the more extreme the value from the
population mean, the more room there is to
regress to the mean. So, whenever a group is
selected with extreme values for one variable
and another variable is then measured, the
regression effect is high.
Explanation : The reference period is the time frame for
which survey respondents are asked to report
activities or experiences of interest. Many
surveys intend to measure frequencies of
events or instances within a given period
of time. Most of the time, the reference
period starts at some point in the past and
ends at the time of the survey. However,
there are fixed reference periods as well.
Explanation : Direct teaching is a teacher-directed method
(teacher facing and instructing a class)with
the use of straightforward, explicit teaching
techniques to teach a specific lesson or skill.
Therefore, providing examples and explanation
(i); giving review and recapitulation (iv); and
offering practice and feedback are strategies
of direct teaching method.
Promoting inquiry (ii); focussing on concepts
(iii); and offering practice and feedback (v)
are student centred methods of teaching.
Explanation : There are two Main Types/Categories of
tests: I. Maximum Performance Tests
2. Typical Response Tests
Maximum Performance Tests are designed
to test knowledge and abilities because of
which responses can either be correct or
incorrect. Ex. Achievement & Aptitude test.
Typical Response Tests measure things like
personality, behaviour, attitudes or interests.
Ex. Objective & Projective personality tests.
Explanation : Non-probability sampling is a sampling
technique which does not give all the
individuals in the population equal chances
of being selected, e.g.,
Convenience Sampling - selecting samples
that are accessible to the researcher or easy
Consecutive sampling - selecting all
accessible subjects making the sample a
better representation of the entire population.
Judgmental Sampling or purposive sampling
- selecting with the belief that some subjects
are more suitable than other individuals for
Snowball Sampling - selecting a subject who
is asked to identify another potential subject
meeting the research criteria (Snowball
sample is hardly representative of the
Quota Sampling - selecting sample
that ensures equal or proportionate
representation of subjects per trait considered
as basis of the quota for a given sample size.
Dimensional Sampling (an extension of
quota sampling) - the researcher takes
into account several characteristics (e.g.
gender, income, residence and education)
and ensures that there is at least one person
in the study representing each of the chosen
Probability sampling, on the other hand,
utilizes some form of random selection
method that ensures that the different units
in the population have equal probabilities of
being chosen, e.g.,
Simple Random Sampling - drawing a
name out of a lot, or using computers for
generating random numbers.
Stratified Random Sampling - randomly
selecting from smaller group divisions of a
large population that usually don't overlap
but represent the entire population together.
Cluster random sampling - randomly
selecting participants from selects areas
(Le. cities or counties) when they are
geographically spread out.
Systematic Sampling - randomly selecting
every ''nth'' individual to be a part of the
sample according to a random starting point
and a fixed periodic interval.