2. CONTENT
Sample
Sample size
Characteristic of sample size
Determination of sample size
Determination of sample size through the approach
based on precision rate and confidence level
3. Sample:
Sample “A small portion of the population which truly
represents the population with respect to the study
characteristics .” How much should be the small portion is
determined by computing the Minimum Sample size
Need for sample size:
Need for sample size Biological data is highly variable
Crucial element in the planning of any research project
economy in terms of personnel, equipment's, time and
related aspects but ,not at the cost of a desired
precision, confidence and power
4. CHARACTERISTIC OF SAMPLE SIZE
Large sample size ∝ Accuracy of sample result
It doesn’t guarantee accuracy of result
if sample size (n) not be too small & too large
5. DETERMINATION OF SIZE OF SAMPLE
Nature of universe
homogenous or heterogeneous
homogenous – small sample
heterogeneous - large sample
Number of classes proposed
Class groups increasing sample size all increasing
Nature of study
For a continuous study sample size is small
6. CONT’D-
Type of sample
random sample is apt
Standard of accuracy & acceptable
confidence level
Large sample size is need
Availability of finance
money availability
Determination of size of sample for large sample for large
sample result in increasing the cost of sampling estimation
Other consideration
Nature of units, Size of population ,Size of questionnaire ,
availability of trained investigators &
time
7. DETERMINATION OF SAMPLE SIZE THROUGH THE
APPROACH BASED ON PRECISION RATE AND
CONFIDENCE LEVEL
