Chapter 9 readings this week is about experiments. The learning objectives in this chapter are the used for experimentation, advantages and disadvantages of the experiment method, seven steps of a well-planned experiment, internal and external validity with experiment research designs, and the three types of experiment designs and the variations of each. In chapter 9 experiments is defined as the studies involving intervention by the researcher beyond that required for measurement (McGraw-Hill Company). One of the advantages of experiments is that it comes the closest than any primary data collection to accomplish its goal. One of the foremost advantages is the ability of the researcher to manipulate the independent variable. The second advantage of the experiment is the contamination of extraneous variables being controlled way more effectively in other designs.
This allows researchers to isolate the variable and evaluate the impact. The third is the convenience and cost experimentation that are superior to other methods (McGraw-Hill Company). The benefit of this is that it allows experiment opportunities in scheduling data collection and the flexibility in adjusting the variables. The disadvantages are the artificiality of the laboratory of the experimental method. Second are the samples of nonprobability can pose problems despite the random assignment. Conducting a well-executed experiment must have a complete series of activities in order to have a successful experiment. In chapter 9 Exhibit9-1 it gives researchers seven activities that a researcher must accomplished in order to have a successful research. Exhibit 9-1
1. Seven relevant variables.
2. Specify the treatment levels.
3. Control the experiment environment.
4. Choose the experimental design.
5. Select and assign the subjects.
6. Pilot test, revise, and test.
7. Analyze the data.
Researchers are task to translate an amorphous problem that is being question or the hypothesis that is best state of the objectives the research (McGraw-Hill Company. The book mentioned that hypothesis is a relational state because it describes a relationship between two or more variables (McGraw-Hill Company). It also be operationalized, a term we used earlier in discussing how concepts are transformed into variables to make them measurable and subject to testing (McGraw-Hill Company). Researches challenges are: 1. Select variables that are the best operational representations of the original concepts. 2. Determine how many variables to test.
3. Select or design appropriate measures for them (McGraw-Hill Company). Controlling the experimental environment variables may appear in differences in age, gender, race, dress, communications competence, and many other characteristic (McGraw-Hill Company). Environmental Control is defined as holding contrast the physical environment of the experiment (McGraw-Hill Company). Other forms of experiment are the control of the subjects. Subjects that are that have no knowledge that they are receiving experimental treatment are said to be blind.
Double blind is when the experimenters do not know of the treatment of the experiment group or the control group. Experiment design is unique in the experiment method. As it serves as a positional and statistical plan to designate its relationship between the experimental treatments and experimenters observations (McGraw-Hill Company). When conducting an experiment the researchers apply their knowledge in order to select the design that is best suited for the goals research. When analyzing data if must have adequate planning. Researchers have several measurements and instrument options with experiments (McGraw-Hill Company). Observational techniques and coding schemes.
Self-report instruments with open-ended or closed questions. Scaling
Physiological measures (McGraw-Hill Company).
Even though there are different types of validity the two major varieties that are considered are internal validity and external validity. Internal Validity among its many threats seven are consider: History
External validity among its threats the following are its interactive possibilities: Reactivity of testing on X.
Interaction of Selections and X.
Other reactive factors.
Author Donald R. Cooper, Pamela S, Schindler. 2011 McGraw-Hill Comapny