6 Lab Experiments and Quasi Field Experiments mailto

6 Lab Experiments and Quasi (Field) Experiments 中央大學. 資訊管理系 范錚強 mailto: ckfarn@mgt. ncu. edu. tw 2010. 03 中央資管：范錚強 1

Learning Objectives Understand. . . Uses for experimentation. Advantages and disadvantages of the experimental method. Seven steps of a well-planned experiment. Internal and external validity with experimental research designs. Three types of experimental designs and the variations of each. 中央資管：范錚強 2

Causal Evidence Agreement between IVs and DVs Time order of occurrence Extraneous variables did not influence DVs 中央資管：范錚強 5

Experimentation in the Research Process 中央資管：范錚強 6

Conducting an Experiment Specify treatment variables Specify treatment levels Control environment Choose experimental design Select and assign participants Pilot-test, revise, and test Collect data Analyze data 中央資管：范錚強 12

Experiment: Placement of Benefits Module 中央資管：范錚強 13

Measurement Options Observation Physiological measures Paper-and-pencil tests Options Scaling techniques 中央資管：范錚強 Selfadministered instruments 14

Validity in Experimentation Internal External 中央資管：范錚強 15

Threats to Internal Validity Maturation Experimental mortality History Threats Statistical regression Testing Instrumentation Selection 中央資管：范錚強 16

Additional Threats to Internal Validity Diffusion of treatment Compensatory equalization Compensatory rivalry Resentful disadvantaged Local history 中央資管：范錚強 17

Threats to External Validity Reactivity of testing on X Interaction of selection and X Other reactive factors 中央資管：范錚強 18

Experimental Research Designs Pre-experiments True experiments Field experiments 中央資管：范錚強 19

Selecting and Assigning Participants Random assignment 中央資管：范錚強 Matching 20

Quota Matrix Example 中央資管：范錚強 21

實驗設計的一些慣用符號 X: manipulation 操弄 O: observation 觀察 R: random assignment 隨機分派 M: matched pair assignment 配對分派 中央資管：范錚強 22

實驗設計：假實驗 Pre-experimentation (One-Shot) After-Only Case Study X Pre-experiment O 中央資管：范錚強 23

One Group Pretest-Posttest Design O 1 Pre-experiment X 中央資管：范錚強 O 2 24

Static Group Comparison X O 1 O 2 Pre-experiment 中央資管：范錚強 25

真實驗 True Experimentation Posttest-Only Control Group Design R R True experiment X O 1 O 2 中央資管：范錚強 26

Pretest-Posttest Control Group Design R R O 1 O 3 X O 2 O 4 Effect= (O 2 - O 1) vs (O 4 - O 3) Deal well with the major internal validity problems True experiment 中央資管：范錚強 27

真實驗 2 Completely Randomized Design E. g. , 3 treatment levels R R R O 1 O 3 O 5 X 2 X 3 X 5 O 3 O 4 O 6 中央資管：范錚強 28

真實驗 3 Completely Randomized Design E. g. , 3 treatment levels R R R O 1 O 3 O 5 X 2 X 3 X 5 O 3 O 4 O 6 中央資管：范錚強 29

真實驗 4 Randomized Block Design Active Factor 7 cents R 12 cents R 17 cents R Blocking Factor High Medium X 1 X 2 X 3 中央資管：范錚強 Low X 1 X 2 X 3 30

真實驗 5 Latin Square Design Store Size Large Medium Small Customer Income High Medium X 3 X 1 X 2 中央資管：范錚強 Low X 2 X 1 X 3 31

真實驗 6 Factorial Design Price Spread Unit price information? 7 Cents 12 Cents 17 Cents Yes X 1 Y 1 X 1 Y 2 X 1 Y 3 No X 2 Y 1 X 2 Y 2 X 2 Y 3 Covariance Analysis 中央資管：范錚強 32

Field Experiments: Quasi- or Semi-Experiments Non Equivalent Control Group Design Separate Sample Pretest-Posttest Design Group Time Series Design 中央資管：范錚強 33

Nonequivalent Control Group Design O 1 O 3 Field experiment X O 2 O 4 中央資管：范錚強 34

Separate Sample Pretest-Posttest Design R R Field experiment O 1 中央資管：范錚強 (X) X O 2 35

Group Time Series Design R R Field experiment O 1 O 2 O 3 X O 4 O 5 O 6 O 7 O 8 O 9 O 10 O 11 O 12 中央資管：范錚強 36

Job Enrichment Quasi. Experiment 中央資管：范錚強 37

主效果和互動效果 Main effect Interaction effect The influence of a single independent variable on a dependent variable. 中央資管：范錚強 The influence on a dependent variable by combinations of two or more independent variables. 38

2 x 2 Factorial Design Ad A Ad B Men 65 Effects > Main of Gender Women 65 70 60 > Main Effects of Ad 中央資管：范錚強 39

變數互動 Believability 100 Wo me n 90 80 70 Men 60 50 40 30 20 10 Ad A 中央資管：范錚強 Ad B 40