Quasi-Experimental Designs - Essay Example

? Quasi-Experimental Designs Quasi-Experimental Designs: Assignment Question The single group posttest design only shall apply to the study, which attempts to indicate the effectiveness of weekly quizzes in improving student learning (Trochim & Donnelly, 2008). Question 2 The professor should use the single group pretest/posttest design to assess the effectiveness of the weekly quizzes. The professor should administer the quizzes to the section of the class twice. Conducting first assessment takes place before administering weekly quizzes while the second assessment is done after the administration of questions to the class (Trochim & Donnelly, 2008). The two assessments are then compared, and the differences in both of them shall be taken to be the result of the effectiveness of the quizzes. The single group pretest/posttests design is recommended for this study (Jackson, 2009). Question 3 The possible confounds in each of the studies outlined include the notion that in the case of single group posttest design, the study does not provide for comparing the measures or variables. In the second study, the single group pretest/posttests design does not provide for how the observed changes in the study can be determined (Jackson, 2009). In this case, if the weekly quizzes are effective in improving learning, it is not possible to determine whether other factors contributed to the improved learning among students (Jackson, 2009). Therefore, in the absence of a comparison group, it becomes exceedingly difficult to determine whether the observable changes are because of the weekly quizzes or because of students taking more time to read at home. Question 4 Researchers might choose to use a single-case design when they want to ensure sensitivity to the individual participant variation versus group designs that show sensitivity to averages of factions (Trochim & Donnelly, 2008). Secondly, the single-case design is also applicable when researchers have intent to assess the effect of diverse interventions in functional research. Thirdly, researchers might use this design when they need highly flexible ways of showing individual variations in responses to intercession effects (Jackson, 2009). Furthermore, the single-case design minimizes interpretation biases among researchers. Question 5 Multiple baseline design entails the careful assessment of multiple individuals, characteristics, or settings both prior to and following intervention while a reversal design entails a study where introduction of interventions starts after the baseline interlude and is then withdrawn in the second baseline period. Quasi-experimental designs have both positive and negative aspects. Firstly, quasi-experimental designs are highly applicable in cases where randomization appears impossible or immoral because they are easier to set up compared to the true research designs requiring haphazard assignment of subjects. Further, the design diminishes external validity threats since natural settings cannot suffer similar predicaments as compared to artificial or controlled research environment (Trochim & Donnelly, 2008). The design also permits the researchers to apply the findings to other subjects and environment, thus allowing for generality about population since all research is conducted under natural settings. The disadvantages associated with quasi-experimental designs include the possibility of confounding variables to pollute findings. In this study, for example, improved students learning may result from other factors but not only the weekly quizzes (Jackson, 2011). There is a lack of randomization in this design, which creates significant challenges to researchers since it makes it harder to eradicate confounding variables and initiates fresh internal validity threats (Trochim & Donnelly, 2008). Furthermore, the design allows for making conclusions about findings without understanding causal relationships. This is because the establishment of causation becomes impossible since the researchers lack full control over unrelated variables (Jackson, 2011). The fundamental weakness of quasi-environmental experiments is the inability to generate clear findings because of the internal validity threats and lack of randomization. This is a weakness because internal validity threats and lack of randomization make it hard to determine the relationship between findings and causality (Trochim & Donnelly, 2008). The weakness always matters because sometimes the findings generated are not the true picture of the situations. Question 7 When participants are randomly assigned to groups, one can assume that they are equivalent at the beginning of the study because this forms the baseline period (Jackson, 2011). At the end, it is assumed that the groups are different because the intervention or treatment is expected to result into certain changes. Researchers should consider studying whether confounding variables present challenges to obtaining equivalence (Jackson, 2011). This can be done by undertaking the study under a non-controlled environment in order to determine the relationship between variables and findings. Question 8 It is possible to determine the presence of particular threats in studies outcome by looking at the findings of studies against those expected. In quasi-experimental designs, external factors always threaten internal validity (Jackson, 2011). This is because, in the ideal condition, it should be possible to establish the relationship between findings and causality. For example, in the case of administering weekly quizzes to determine their effectiveness in improving student learning, the single group pretest/posttests design enable the researcher to know that students who take their time to read could perform better, but not only because they take the quizzes (Trochim & Donnelly, 2008). Question 9 Non-equivalent control group pretest only entails the situation where a researcher randomly assigns participants to different groups in a pretest period. On the other hand, non-equivalent control group pretest/posttest entails a situation where a researcher ensures that participants assigned to groups randomly are assessed before and after interventions (Trochim & Donnelly, 2008). Cross-sectional control allows researchers to study differences in cross-age groups. Regression discontinuity is a useful method that researchers employ in determining the effectiveness of any intervention or treatment program. It is a pretest/posttest program-assessment grouping strategy where researchers assign participants to comparison groups using a cutoff score during preprogram assessments. Question 10 Quasi-experimental designs are applicable in certain research studies more than experimental designs because of their uniqueness. They are used more than experimental designs in cases where researchers do not want to assign participants randomly to groups and where there is a need to manipulate an invalid variable in order to realize cause-effect conclusions (Jackson, 2009). It is notable to recognize that within the research cycles, there is no existence of bad designs. However, researchers need to recognize that sometimes they make bad design choices at the implementation of a study, thus affecting their outcomes. Question 11 Single-group posttest-only design can also yield relatively unambiguous findings. For instance, a question that seeks to understand how individuals who joined a particular group have experienced changes and associate them with effects of joining those groups. Therefore, the question could be: do people who participate in group discussions in schools eventually pass their exams better than those who do not participate? Quasi-Experimental Designs: Assignment 2 Question 1 The study addresses the questions that TV advertising involving children’s toys and cereals influences their choices for these items since they recognize them from the adverts (Goldberg, 1990). Question 2 The rational for the study is to show that TV adverts have influencing factors on the children who watch them (Goldberg, 1990). The study is designed to contribute to this theory because, for an exceptionally long time, other researchers have made conjectures that watching TV adverts is an effective marketing tool because of its ability to influence potential buyers. The quasi-experimental designs enable the generation of findings that contribute to the theory. This is because various designs attempt to show that under controlled settings where children are made to watch TV advertisements, they are likely to recognize items they have watched (Goldberg, 1990). However, in a natural environment, the additional influences or factors ensure that their concentration when watching TV adverts reduces. In both cases, a correlation is evident between commercial TV advertisements targeting children and the youngsters’ preferences and buying choices. Question 3 The study addresses two constructs premised on the notion that laws prohibiting advertising targeting children in Quebec stopped them from accessing and watching youngsters’ products on the Quebec TV stations. Secondly, it is premised on the view that children who speak English watched more adverts from the American Children’s Commercial TV (ACTV) than their French-speaking counterparts did (Goldberg, 1990). These constructs are operationalized by doing between group analyses and within group analysis. This operational method revealed that in the between-group analysis, English speaking youngsters responded more positively than French speaking kids did when they watched similar children products on ACTV. On the other hand, when children speaking the two languages watch the same amount of ACTV, their response to advertised products appears similar (Goldberg, 1990). In the case of within-group analysis, when the children from both language divides watch more ACTV, they respond more positively to advertised products than when they watch little of the same adverts. Question 4 The independent variables in this study under the between group analysis are the cultural affiliation of the different groups in terms of the language they speak (Goldberg, 1990). In addition, in within-group analysis, the independent variable was determined using a TV guide to enable estimation on the total number of ACTV programs every youngster had watched in a year. The dependent variables include the underlying subject under study such as children’s awareness of toys and cereal purchases. Question 5 The single group pretest/posttest design is applicable for this study since it assesses the effectiveness of advertisement of children products on TV in influencing the youngsters’ preference for such items and in increasing their purchase choices (Goldberg, 1990). The design is appropriate because it enables researchers to measure differences among children who watch the advertisements and those who have less exposure to it. The resulting differences are assumed to be because of the TV advertisements. Question 6 The researchers addressed the internal validity threats of varying cultural orientation between the English- and French-speaking children, which caused them to exhibit awareness to toys and cereals differently (Goldberg, 1990). The researchers employed a two-pronged strategy to address this situation (Goldberg, 1990). First, the researchers considered every language group differently where they managed to show an association between the levels of watching ACTV to toys awareness and cereals purchase. Secondly, the emergence of external validity threats was shown by the finding that when the English- and French-speaking youngsters watch ACTV at equal levels, they purchase equivalent amounts of cereals. On the other hand, watching ACTV for equal lengths of time generated different findings (Goldberg, 1990). The English-speaking children recognized more as compared to French-speaking youngsters. This is an indication that other factors on top of viewing ACTV resulted into the difference. The researchers introduced the level of income as the third variable in the investigation to show that income is a factor to the number of toys that children can recognize (Goldberg, 1990). References Goldberg, N. (1990). A quasi-experiment assessing the effectiveness of TV advertising directed to children. Journal of Marketing Research, 27, 445-454.  Jackson, S. L. (2009). Research methods and statistics: A critical thinking approach. Belmont, CA: Wadsworth Cengage Learning. Jackson, S. L. (2011). Research methods: A modular approach. Belmont, CA: Wadsworth/Cengage Learning. Trochim, W. M. K., & Donnelly, J. P. (2008). Research methods knowledge base. Mason, Ohio: Atomic Dog/Cengage Learning. Read More