I think that Lesson 16 was the turning point for me concerning the writing of my Research Proposal. I feel like I am starting to understand the purpose of the proposal and how it is to be written. In Lesson 18, Dr. Norman indicated that the researcher should mention weaknesses and limitations of his or her experiment in the Procedures part of the Methodology section, and this practice is not unlike what any scientist would do when performing experiments. Now, I recall my earlier confusion in the opening lessons concerning the scientific approach and where we were headed, and perhaps, those initial loose ends in my understanding are starting to come together.

The key characteristics of experiments are very logical, as are the general aims of experiments. The experiment should have a clear purpose, and the researcher should be able to control, manipulate, and observe the right variables at the right time. The experiment should also show the relationships between the key variables and make it possible for the researcher to establish some general laws about those relationships.

However, most of Lessons 18 and 19 were about the four types of experimental validity because experiments can be weak or faulty. By construct validity, I think that Dr. Norman was saying that the experiment needs to satisfy some basic construction rules, such as carefully defining the variables and clearly stating how they will be measured. To me, this is just another way of saying that the experiment must have a strong design. By statistical conclusion validity, my understanding was that the experiment must be able to ensure statistical integrity and that the conclusions are an accurate picture of truth. The researcher would not want to establish a general law about the relationship between a dependent and independent variable and then have that law be faulty because of bad statistical procedures. Internal and external validity also seemed highly dependent on the use of solid statistical techniques.

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Lesson 20. Experimental Designs (Part I)

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