2. Abstract
Measurement
Issues related to the validity and reliability of measurement
instruments used in research are reviewed.
Scale
A scale is a set of numerical values assigned to subjects, objects,
or behaviors for the purpose of quantifying the measuring
qualities.
Sample
A subset of a population selected for measurement, observation
or questioning, to provide statistical information about the
population
3. Introduction to Research Methodology
A science of studying how research is done
scientifically
A way to systematically solve the research
problem by logically adopting various steps
Methodology helps to understand not only
the products of scientific inquiry but the
process itself
4. Measurement
Instrument
Instrument is the generic term that researchers use for a
measurement device (survey, test, questionnaire, etc.).
Validity
Validity is the extent to which an instrument measures what it
is supposed to measure and performs as it is designed to
perform.
Reliability
Reliability can be thought of as consistency.
5. Scaling
Used as a measuring instrument.
Used to indicate a measuring instrument.
Used to indicate the systematized numerals of the measuring instrument.
Tests are scales, but scales are not tests.
Attitude
is an integral part of the personality (as to the way we think, feel, perceive,
and behave toward a cognitive objective).
Attitude scales have three major types
I. summated rating scales
II. equal appearing interval scales
III. cumulative or Guttman scales
6. Sampling
Probability Sampling
refers to sampling when the chance of any given
individual being selected is known and these individuals
are sampled independently of each other. This is also
known as random sampling.
Non-Probability Sampling,
or convenience sampling, refers to when researchers
take whatever individuals happen to be easiest to
access as participants in a study.
7. Conclusion
Key indicators of the quality of a measuring
instrument are the reliability and validity of the
measures. The process of developing and
validating an instrument is in large part
focused on reducing error in the measurement
process . Scaling Intensity of attitude
expression . Probability Sampling &Non-
Probability Sampling
