CH1- Data collection

CH1- Data collection

1. Population- The whole set of items that are of interest

2. Sample- Same subject of the population intended to represent the population

   • Advantages- Cheaper, quicker and less data to progress
   • Can not be accurate. May not be large enough to represent small sub groups.

3. Sample Unit- Individual thing is the population that can be sampled

4. Sample Frame- Individually named or numbered from a list

5. Census- entire population

   • A-Completely accurate
   • D- Time, cannot be used when testing, Large volume of data to process

6. Random sampling- equal chance to be chosen to avoid bias. Method: each item has identifying number. Use random number generator

   • A- Easy, cheap, Equal chance
   • D- Not suitable for large data set. sample frame needed

7. Systematic- required element are chosen at regular intervals in ordered list. K=pop size/ sample size

   • A- Simple, quick, large sample suitable
   • D- sample frame, can be biased
   • Q= he should divid 50,000 by 100 to get every 50th person

8. Stratified sampling- population divided into groups(strata) simple random sample carried out in each group. Sample size(a)/pop size(n)

   • A- Reflects population structure, insure proportional representation
   • D- must be clearly classified into distant strata

9. Quota- Divided into groups in characteristics

   • A- Allows small sample, No sample frame, Quick and easy, Easy comparision
   • D- Can be biased, costly,inaccurate, time

10. Opportunity-You can study people into groups through poll or survey

    • A- easy to do, Inexpensive
    • D- Unlikely to give presentation sample, highly dependent on individual researches

11. Quantitative- Numerical values

12. Qualitative- Non numerical values

13. Continuous data- you can measure with decimals

14. Discrete- Exactly count