1. 3/5/2009Computer systems1 Information Gathering Unobtrusive methods: Sampling Investigation Observing a decision maker’s behavior Observing the physical environment

2. 3/5/2009Computer systems2 Sampling n Need n Design n Size

3. 3/5/2009Computer systems3 The Need for Sampling Reasons: n Containing Cost n Speeding up the data gathering n Improving Effectiveness n Reducing Bias

4. 3/5/2009Computer systems4 Sampling Design Design Steps: n Determine the data to be collected n Determine the population to be sampled n Choose the type of sample n Decide on the sample size

5. 3/5/2009Computer systems5 Data What to do with the collected data? Identify: n Variables n Attributes n Associated data items

6. 3/5/2009Computer systems6Population n Time? ( last two months or whole year? ) n Whom? – one level or all the levels? – customers? – vendors? – suppliers? – competitors?

7. 3/5/2009Computer systems7Type Chose one of the four main types: n Convenience n Purposive n simple n Complex

8. 3/5/2009Computer systems8Size Seven steps: 1. Determine attribute 2. Locate database or reports 3. Estimate the proportion of the population 4. Estimate the acceptable interval 5. Choose confidence level, confidence coefficient 6. Calculate standard error 7. Determine sample size

9. 3/5/2009Computer systems9Investigation The act of : n discovery of data n analysis of data

10. 3/5/2009Computer systems10 Decision Maker’s Behavior Observing decision-making : n activities

11. 3/5/2009Computer systems11 Physical Environment STRuctured OBservation of the Environment (STROBE) seven elements 1. Office location 2. Desk placement 3. Stationary office equipment 4. Props (Properties) 1.small equipment to process information 5. External information sources 6. Office lighting and color 7. Clothing worn by decision makers