Whatis the purpose of conducting an experiment? How does an experimentaldesign accomplish its purpose?

Conductingastudy enables the researcher to come up with various conclusions onthe issues at hand. The experiment offers a scientistwitha possible cause-effectexplanation for the differentsituations in the study. Thisiscarried out through the observation of the variables, which aremanipulatedas per the requirements of the researcher and the investigation.Manipulation of the environment of the research takes place when theresearcher has a keen target of seeing the reaction of the variablesand their significance in the study. The experimental design standsto have an integral function in the whole course of the research.Understanding the innovativedesign equips one with the knowledge of how systems operate and theirsignificance to the study (Trochim &amp Donnelly, 2008).

Therefore,the experimentaldesign helps to ensure that the tentative groups, the control, andthe environments are as similar in a necessaryway. The variables are well put intoconsideration when using the experimental design. Each study has aunique experimentaldesign whose primary aim is to establish the best performance for theexperiment and come up with the greatest results. The experimentaldesign helps to make one study have the best results and gain withthe specific control groups. With an efficient experimental design, astudy has a higher chance of effective and efficient results.

Whatare the merits and demerits ofexperimentaldesign in an educational study?

Internalvalidity is a component of a substantial experiment. The validityenables a researcher to look into the various causes and effects ofspecific items in the investigation. For asubstantialvalidity ofresearch,the environment of study deserves greater degrees of control from thescholars. The controlin the environment of studyshould be matched up with a well-calculated group as well as a bigsample for the entire experiment. Despite the fact that internalvalidity stands out as a great component for the efficientresearchers,it also acts asanimitation.Internal validity limits the way in which the researchers arerequired to generalize the results of the experiment. The operationsneeda stimulativeform of outlook, which would reveal the way in which the contexts arehandled.Due to the over- application of the internal validity, the externalvalidity of the study is considered as weak in anactualexperiment (Trochim &amp Donnelly, 2008). Therefore, in aneducational study, the external validity deserves to be lowto achieve concrete results and efficient outcomes.

Experimentsare greatly composed of the variables of the survey.The variable should be controlled invarious ways to enable the justification of the intended points.Through the manipulation of the variables in an experiment, theresearcher achieves the desired results. The testsarehandledin an ethically proven manner, which also makes the scientiststo have stipulated way of carrying out the study. Theissue makesit necessaryfor the members of the research team to control their groups toenable them achieve desirable results. In most cases, theenvironments are monitoredsince the real world has numerous items affecting it. Therefore, theaction of the experiments might be under the influence of variousfactors.

Whatis more important in an experimental study, designing the study tomake strong internal validity claims or strong external validityclaims? Why?

Internaland external validity contribute to the formation ofvalidresearch. Through the making of a platform for the two to relate, itis noticeable that the two have a negative correlation, the more a study tends to draw towards having a greaterinternal validity, the greaterthe chances of having a weaker external validity (Creswell, 2009). Therefore, the two variables of efficacydo not complement one another rather the existence of one marksthe lifeof another, thus the negative relation.

Inan experiment, what is a control? What is the purpose of a controlgroup? Of single or multiple comparison groups?

Whileconducting aninvestigation,it is integral that the study has a member of the sample, which actsas a reference to the changesin the experimental group. The division of the sample into twoprovides a platform for the carrying out of the experiments. Thecomparison of the results is a group, which has been manipulated bythe variables, and a group, which is normal inthe controlled environment (Jackson, 2012). Therefore, through thecontrol group, which does not have the same treatment as theexperimental team, the researcher candetermine the direction for the study. Moreover, the singlecomparison groups base on the fact that the experimental groups andcontrol groups are in the experiment. The study uses both of them todetermine the treatmentif it producesa better result than nontreatment(Jackson, 2012). The multiple groups, manipulation,is at peak and the experimental groups are undergoing control tomanipulate the results as per the requirements of the experiment.Therefore, the study is well catered for in this case.

Whatare confounds? Give an example of a design that has three confounds. Describe three ways to alter the design to address these confoundsand explain the advantages and disadvantages of each.

Confoundsare typical errors that exist in the course of an experiment. Variouskinds of stuns canbefoundinan experiment (Leedy &amp Ormrod, 2010).For an instance when astudy comes out with ambiguous findings, that is referred to asconfounds. The misperceptions can also exist when a single variablein the study was not under control in the course of the entireexperiment (Trochim &amp Donnelly, 2008).

Theone-shotexperiment is an example of a three confounds research design. Inthis studydesign, treatment to the variable exists and a measurement also comesin handy to look at the effect of the treatments.There are various effects which affect the study as at this pointthat isassumingthe use of the design. Some of the mistakes that can exist in theresearch design include the history effect, subject effect anddiffusion effect. The altering of the method to have a double designwould ameliorate the efficiency of the experiment. This model,on the other hand,has adverseconsequencesonthe overall results of the study. Therefore, it is not advisable touse it in most instances.

Whatdoes “cause” mean and why is it an important concept in research?How are correlation and causation related?

Withina study or an experiment, the causeis a term that describes factors that lead to various events. Inresearch, when determiningthe specific cause of an object resultsinthe making of areasonableconclusion fromthe researchers (Crosby &amp Bates, 2012). Moreover, the causealways comes before the effect. The impact cannot exist without thecause for a standardissue. Correlation and causation have a unidirectional relationship.For an instance when x happens, Y tends to happen and when X does nothappen, so does Y.

Youare a researcher interested in addressing the question: does smilingcause mood to rise (i.e., become more positive)?Sketch between-participants, within-participants, andmatched-participantsdesigns that address this questionand discuss the advantages and disadvantages of each to yielding datathat help you answer the question. Describe and discusseach design in 4-5 sentences.

Betweenparticipants design-this involves the random selections of membersfromaparticularpopulation. The groups are made to undergo various variables, whichhelp in determining the moods of the individuals. Through the groups,half of the selected population can be doneto smile while another acts as a control sector. The model hasvarious assumptions, which lead to the depreciation of effectiveness,this model assumes equivalence to the differentgroup,and they also require a sufficient enough team to address theconcerns. Nonetheless, the model is a veryefficientone since it reduces the instances of confounds.

Withinsubject design-This involves the selection of a single entity fromthe population. The planwill call for half of the group to smile while the other half willnot smile. The assessment would come in the shapeof those that heard the opposite of the instructions and acted so.The design does not require a control group since the subjects isprojectedto various tests and time is a factor efficiently saved. However, thedesign holds greater extents of being confounded.

Matchedsubjects design-The design involves the selection of two random groups and theexperimental plus control teams aretestedforrelevanceto the subjectof the study. Various variables are produced to ensure that thespecific subjectsarewell coveredin this design. Assumptions aremadefrom the matching of subjects with similar traits. It helps in thecreation of a more concrete solution. Nonetheless, it is exposed tomortality confound.


Cozby,P. C., &amp Bates, S. C. (2012). Methodsin behavioral research(11th ed.). Boston, MA: McGraw Hill Higher Education.

Creswell,J. W. (2009). Research design: Qualitative, quantitative, and mixedmethods approaches (3rd ed.). Thousand Oaks, CA: SAGE.

Jackson,S. L. (2012). Researchmethods and statistics: A critical thinking approach (4thed.). Belmont, CA: Wadsworth Cengage Learning.

Leedy,P. D., &amp Ormrod, J. E. (2010). Practicalresearch: Planning and design.Upper Saddle River, NJ: Merrill.

Trochim,W. M. K., &amp Donnelly, J. P. (2008). Theresearch methods knowledge base (3rded.). Mason, OH: Cengage Learning.