Experimental Design

Three type of research designs:

Experimental
Identify causation
Manipulates variables
Random assignment

Quantitative Observational
Treatment groups pre-existing
No random assignment, hence cannot identify causation
No manipulation, only observation to identify correlation of variables

Qualitative
Non-experimental, like quantitative observational only there is nothing quantitative about it, all interpretion/opinions

All three can collect two kinds of Data, Qualitative and Quantitative.

* * *

Experimental Design;

influenced by extraneous variables,

• Participant variables
• situational variables
• experimenter variables
• placebo effect

Advantages

• More control over extraneous variables
• Can prove causation by manipulating IV to affect DV
• Can replicate experiment

Disadvantage

• May be unethical
• Not applicable to real world

Quantitative Observational

Advantages

• Allow investigation of variables otherwise too costly, unethical or impossible
• Some behavior can only be studied using a naturalistic setting

Disadvantages

• Cannot infer a strong cause/effect due to greater chance of other variables influencing results, due to lack of random assignment

Qualitative
Answers a question instead of testing a hypothesis/prediction
Investigates difference between groups and Association between variables

Advantages

• Investigate complex real world issues
• Open ended approach provides important information
  

Disadvantage

• Chance of experimenter bias

Focus Group Method

Advantage

• Richness of generated data
• Easy to organize
• Inexpensive
• Safety in numbers principle
• Can collect info from uneducated people

Disadvantages

• Lack of confidentiality
• Unease disagreeing with large groups
• Not representative of other groups

Delphi Technique

Advantages

• Does not require participants to be at the same place at the same time
• Maintains confidentiality
• Minimizes disadvantages associated with group decision making

Disadvantages

• Forces consensus
• No discussion