Posted: December 5th, 2016

When you have a True experiment it is because you have decided to assign to groups randomly.

Discuss why you do or do not agree with these description.  Be sure to provide constructive and professional feedback.

• When designing an experiment a few decisions have to be made to decide the type of experiment it will be. When you have a True experiment it is because you have decided to assign to groups randomly. If this is not done then it will be either quasi-experiment or non-experiment. From here it must be decided if there is a control group/multiple measures or not. If there is multiple measures or a control group but nothing was assigned randomly then you have a quasi-experiment, “Under such circumstances, researchers have little control over the delivery of an intervention and have to plan an evaluation around a proposed intervention” (Eccles, Grimshaw, Campbell & Ramsay, pg.50, 2012).If there is no random assignment and no control group or multiple measures then you have a non-experiment
• There are a variety of threats to acceptance of validity. Some of these threats which can cause results not to be accepted by peers can include (Types, n.d.):
• Inappropriate selection of constructs or measures.
• Insufficient data collected to make valid conclusions.
• Measurement done in too few contexts.
• Measurement done with too few measurement variables.
• Too great a variation in data.
• Inadequate selection of target subjects.
• Complex interaction across constructs.
• Subjects giving biased answers or trying to guess what they should say.
• Experimental method not valid.
• Operation of experiment not rigorous.

• Reliability and validity are independent of each other. A measurement maybe valid but not reliable, or reliable but not valid. Torchim (2006) sees them instead of being distinct rather as a continuum. On one end is the situation where the concepts and methods of measurement are the same.