Sampling Methods Project Trimester-SS-2006/08

Convenience Sampling Population elements are selected based on the judgement of the researcher. Chooses the elements to be included because he/she believes they are representative of the population

Population elements are selected based on the judgement of the researcher.

Chooses the elements to be included because he/she believes they are representative of the population

Cluster Random Sampling The target population is divided into mutually exclusive and collectively exhaustive clusters or sub-populations. Then a random sample of clusters is selected For each selected cluster, either all the elements are selected or a sample of elements is drawn probabilistically.

The target population is divided into mutually exclusive and collectively exhaustive clusters or sub-populations.

Then a random sample of clusters is selected

For each selected cluster, either all the elements are selected or a sample of elements is drawn probabilistically.

Cluster Random Sampling Take the population map. Divide it into equal clusters Assign each cluster a random number. Select the cluster/s on the basis of a pre-decided rule. Divide the selected cluster into sub-clusters. Repeat steps 2-4 until you get a manageable sub-cluster.

Take the population map.

Divide it into equal clusters

Assign each cluster a random number.

Select the cluster/s on the basis of a pre-decided rule.

Divide the selected cluster into sub-clusters.

Repeat steps 2-4 until you get a manageable sub-cluster.

Example

Divide Map/Population into clusters

Assign Random numbers http://www.graphpad.com/quickcalcs/randomn2.cfm Select Random numbers on basis of pre-decided rules. E.g. only even numbers Select 1 or more clusters on basis of pre-decided rules e.g. Divisible by 4 Repeat till you get desired number of clusters/sub-clusters

http://www.graphpad.com/quickcalcs/randomn2.cfm

Select Random numbers on basis of pre-decided rules. E.g. only even numbers

Select 1 or more clusters on basis of pre-decided rules e.g. Divisible by 4

Repeat till you get desired number of clusters/sub-clusters

Rule: Numbers ending with 8 951428 927314 804 617017 763089 642931 641204 519153 779451 841581 10 141229 289898 276939 187605 914644 87739 382513 641936 408770 853741 9 399514 60307 397227 505272 998770 244519 509545 440308 726318 307442 8 484145 655607 213772 628139 231825 856150 185553 448950 788757 40342 7 656049 693121 93647 471453 517653 323149 20548 582305 767933 534017 6 70251 456047 206164 383865 902781 668902 258626 204669 891516 464092 5 921971 770869 52066 570811 702775 88556 479995 277732 500513 371968 4 921479 283993 754093 122798 22734 225104 517501 322797 171393 978317 3 470734 325846 920625 516687 99149 436461 923752 180700 243164 613663 2 52895 289377 352029 984050 68495 581353 431706 165126 719935 800968 1 J I H G F E D C B A Row #

Rule: Numbers ending with 8

Rule 2: Select cluster exactly divisible by 8

Rule 2: Select cluster exactly divisible by 8

Thank You!!