Y học - Chapter 4: Developing the Research Plan

Important to most research studies Tentative explanation of the outcome of a research problem In some research in the behavioral sciences, especially descriptive studies, it may be appropriate for the researcher to list objectives rather than hypotheses or to exclude them all together, unless comparisons are being made

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Chapter 4 Developing the Research PlanResearch ApproachesGeneral framework for conducting researchHistoricalDescriptiveQualitativeExperimentalThe general nature of the research problem will determine which approach to useHypothesesImportant to most research studiesTentative explanation of the outcome of a research problemIn some research in the behavioral sciences, especially descriptive studies, it may be appropriate for the researcher to list objectives rather than hypotheses or to exclude them all together, unless comparisons are being madeTypes of HypothesesResearch Hypothesis - An “educated guess” or tentative proposition regarding the possible solution or explanation to the problem being studiedbased on theory or previous research Null or Statistical Hypothesis - A hypothesis of “no difference or no relationship”primary use is for statistical testinghypothesis which says the independent variable has no effect on the dependent variabledoes not necessarily reflect the researcher’s expectationsHypothesis TestingThe Research Hypothesis is transformed into a Statistical or Null Hypothesis (Ho)This is done so that statistical tests can be employed that will determine whether the findings are statistically significant or can be attributed to chanceThe results of the statistical test will enable the researcher to accept or reject the null hypothesisMore Hypothesis Testing The purpose of the statistical test is to evaluate the null hypothesis at a specified level of probabilityFor instance, testing the difference in the mean values between 2 groups at the .05 level means:Do the values of the dependent variable differ significantly (p<.05) so that these differences would not be attributable to chance occurrence more than 5 times in 100?If the null hypothesis is accepted, then the researcher rejects the research hypothesis and concludes there is no difference between the groupsIf the null hypothesis is rejected, then the research hypothesis is affirmed and the researcher concludes there is a significant difference between the groupsExample Research HypothesisIt is hypothesized that children taught by teaching method A will perform better on a reading achievement test than children taught by method BDirection of Expected ResultsDirectional Hypothesis – when the researcher has reason to believe a particular relationship or difference existsChildren with a high IQ are more easily motivated than children with a low IQNondirectional Hypothesis – when the researcher has no reason to believe a particular relationship or difference exists in any directionThere is a difference in the motivational level of children with a high IQ and children with a low IQExample Null HypothesisThere will be no significant difference in reading performance between students taught by method A and students taught by method BorTeaching method has no effect on the reading performance of studentsRule of ThumbResearch which asks DIFFERENCE or RELATIONSHIP questions should always have hypothesesResearch which asks DESCRIPTIVE questions (with no comparisons across groups) may not need hypothesesYou can only reject or fail to reject the null hypothesisData Collection TechniquesThe nature of the study will determine what type of data are required to answer the question and the method of collecting these data Multiple techniques may be used in a single studyThree Basic TechniquesObservation - the researcher may watch the research participants perform and record relevant information about themMeasurement - the researcher may test the research participants or apply a device to measure certain qualitiesQuestioning - the researcher may ask the research participants questions to obtain informationObservation TechniquesDirect observationIndirect observationParticipant observationDirect ObservationResearcher directly observes research participantsResearch participants usually know they are being observedResearcher’s presence might change the way the research participants actIndirect ObservationResearch participants are filmed or videotapedResearcher views tapeParticipant ObservationThe observer participates in the research setting with the research participants, often spending considerable time in the natural setting developing field notesQualitative research methodologyMeasurement TechniquesThis broad category of techniques involves actively testing the research participants on the characteristics of interestAlmost anything can be measured Major categories of measures includePhysicalCognitiveAffectivePrevalent TypesPhysical measurese.g., muscular strength, blood pressure, physiological responses to exercise . . . common in HHPCognitive measures e.g., knowledge on innumerable topicsAffective measurese.g., opinion, attitude, interest, personality traits, motivation, self-conceptaffective factors are often more difficult to capture quantitatively and are typically measured through the use of pencil and paper self-report scalesScaling TechniquesScaling is the process of assigning numbers to the various levels of a particular concept that we wish to measure. Thus, a scale provides an indirect measure of the concept of interestScales can be used to obtain information on almost any topic, object, or subject. Attitude, opinion, behavior, performance, and perception are frequently measured by some type of scaleCommon ScalesRating ScaleSemantic Differential ScaleRank Order ScaleLikert ScaleRating ScaleIndividual items are judged on a single dimension and scored on a linear scale or continuum by selecting a numerical or verbal point on the scale that corresponds to their impression of the itemNumerical Rating ScaleHow important to you is each of the issues listed below:Extremely ExtremelyUnimportant Important 1 2 3 4 5The protection of endangered species of animals ____The improvement of the quality of the air ____The provision of social services to those in need ____Verbal Rating ScaleConcepts No Moderate Greatest Importance Importance ImportanceStaff Discipline ___ ___ ___Communication ___ ___ ___Goal Setting ___ ___ ___Public Relations ___ ___ ___Computer Use ___ ___ ___Administrative Concept ScaleSemantic Differential ScaleA scaling method designed for measuring ones “image” of a selected topic or concept. Subjects will choose a relative position between pairs of bipolar adjectives which describe the topic along a single dimensionNo more than about 20 items should be used. Responses are converted to numeric values and treated statisticallySemantic Differential ScalePlace an “x” in the space on each line below to show your opinion of the pizza served here:Hot ___ ___ ___ ___ ___ ___ ___ ColdBland ___ ___ ___ ___ ___ ___ ___ SpicyFresh ___ ___ ___ ___ ___ ___ ___ StaleSoggy ___ ___ ___ ___ ___ ___ ___ Crisp Rank Order ScaleItems are ranked, usually in terms of preference or importance, relative to each other. This forced ranking results in ordinal scores, thus limiting the statistical treatment of the scoresThe number of items to be ranked should be less than 10, to avoid making the task too difficultRank Order ScalePlease rank the brands of beer listed below in order of preference, with a 1 being the brand you most prefer, 2 being your second choice, and so forth. ____ Budweiser ____ Coors ____ Miller ____ CoronaLikert ScaleA very popular scaling technique which measures the respondent’s degree of agreement or disagreement on an issue, opinion, or particular beliefThe continuum of response typically runs from SA , A, U, D, to SDResponses to a Likert scale can be considered to be interval level scores, thus allowing scores to be summed and treated statisticallyLikert ScalePick a number from the scale to show how much you agree or disagree with each statement: 1 Strongly agree 2 Agree 3 Undecided 4 Disagree 5 Strongly disagreeCollege athletes should be paid ____A woman’s place is in the home ____Participating in sports is all about winning ____Scales & StatisticsSome controversy exists among researchers and statisticians regarding the appropriate statistical treatment of scaled responses If the intervals between score points are presumed to be equal, thus resulting in interval data, the responses can be analyzed statisticallyInterval Level ScalesMost authorities are willing to accept Likert Scales, Semantic Differential Scales, and to a lesser extent Rating Scales, as meeting these assumptions, thus enabling the scores to be treated statisticallyOrdinal Level ScalesOn the other hand, there is virtually no controversy concerning Rank Order Scales such as “Forced Ranking Scales” or “Paired Comparison Scales”Responses constitute ordinal data . . . thus it is inappropriate to perform arithmetic operations or combine responses for a total scale scoreReport frequencies and percentages onlyQuestioning TechniquesWide variety of methods that involve questioning the research participantQuestionnairesStructuredUnstructuredChecklistInterviewsQuestionnairesSurvey research - most common type of descriptive researchUsually self-report questionnaires pertaining to attitudes, behaviors, practices, likes, dislikes, etc.May be mailed, distributed by the researcher or completed onlineMany formatsInterviews Essentially an oral questionnaireMay be personal or telephone interviewsStructured interviewUnstructured interviewFocus Group InterviewEssentially an interview with groups of peopleDesigned to stimulate participants free expression of feelings, beliefs, etc.Requires a skilled facilitator to guide discussionDelphi TechniqueUnique questioning method used to get consensus on a specific issue or topicInvolves obtaining responses from a well-defined group of individualsEach person then reviews his/her position based upon the collective responses from the group and revises position as warrantedMay require several iterationsSelecting the Data Collection MethodWhat type of data is needed to answer the research problem?Factors to considerDemands on the research participantCosts in terms of money, energy, and timeAbility of the researcher to handle the selected technique, including the data analysisData Collection InstrumentsMay include any mechanical or electronic equipment, physical performance task, paper-and-pencil test or scale, as well as a questionnaire designed to collect data on the variable of interestResearcher’s choice of instrument involves deciding if one already exists that can be used as is, if one exists but needs to be revised, or if one needs to be developedInstrument SelectionThoroughly review the literatureIf instrument is found, assess suitabilityReliability - consistency with which it measuresValidity - measures what it is suppose to measureReliability and validity of an instrument are often specific to the age, gender, characteristics of subjects on which it is usedWithout acceptable reliability and validity, the data are of no use in answering the research questionObjective - free from scorer biasAppropriateness to current studyEase of administration and scoringInstrument RevisionIf an instrument is found, but it is not quite acceptable for the current research situation, it may be modified or revisedPermission should be obtained before revising copyrighted instrument developed by someone elseIf changes are major, then it may be necessary to determine new indices of reliability and validity of the revised instrumentInstrument DevelopmentThis is a time-consuming and difficult taskOnly undertake if there is no existing instrument that will sufficeBasic steps include the following:1. Review the literature2. Develop tentative instrument3. Obtain opinions of experts concerning the instrument4. Revise the instrument as needed5. Pilot test the instrument 6. Further revise the instrument as needed7. Finalize instrument
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