Limitations Of A Non Experimental Research

feasible, given time and logistical constraints. A weakness of quasi-experimental research is the lack of random assignment, reducing internal validity. However investigation in real-world conditions increases the external validity. This design could be strengthened by including a control group comparison, comparing HAI rates in another LTCF to determine if there is a similar trend at baseline and at specified collection points.
One study was an uncontrolled before and after study. Pittet et al.’s (2000) study is a landmark study in HH research. Uncontrolled before and after studies are relatively simple to conduct and superior to observational studies. However, the weak design may make it difficult to attribute observed changes to the intervention and overestimate the effects of interventions (Polit & Beck, 2012).
One study had a pretest–posttest design. Pretest–posttest designs can be used with or without control groups. Limitations include threats to internal validity. A two-group control group pretest-posttest design has strong internal validity, because the pretest ensures the groups are equivalent (Polit & Beck, 2012). This design allows researchers to compare the final posttest results between the two groups, indicating the overall effectiveness of the intervention. The researcher can determine if one, both or neither group changed from pretest to posttest. External validity is reduced due to the reactive or interaction effect of pretesting. Data

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