FOUNDATIONS OF NURSING RESEARCH Sixth Edition CHAPTER Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Measurement of Data Collection 12

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objectives 1.Demonstrate An Understanding Of The Concept Of Measurement 2.Differentiate Among The Four Levels Of Measurement 3.Determine The Appropriate Level Of Measurement For Data In Selected Studies 4.Recall Questions To Be Answered In The Data-Collection Process

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objectives 5.Identify Data-Collection Methods 6.Discuss The Selection Of A Data- Collection Instrument 7.List Criteria For Selection Of A Data- Collection Instrument 8.Compare And Contrast Three Types of Reliability

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objectives 9.Compare And Contrast Four Types Of Validity 10.Explain Four Sources Of Error That May Occur In Data Collection 11.Critique The Data-Collection Section Of Research Reports

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective One Learning Objective One Demonstrate An Understanding Of The Concept Of Measurement

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Measurement Process of assigning numbers to variables Ways to assign numbers –Counting –Ranking –Comparing objects or events

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Measurement in Research Quantification of information Numbers are assigned to data. Concept applied with quantitative research designs

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Qualitative Research Designs Concept of measurement does not apply to qualitative data in narrative form. Concept of measurement may apply to qualitative data that is summarized and placed into categories.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Two Learning Objective Two Differentiate Among The Four Levels Of Measurement

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Four Levels of Measurement Nominal Ordinal Interval Ratio

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Nominal Level of Measurement Lowest level of measurement Objects or events are named or categorized. Categories must be exhaustive and mutually exclusive.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Nominal Level of Measurement Examples of nominal level –Gender –Marital status –Religious affiliation

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Ordinal Level of Measurement Second level of measurement Data can be rank ordered and placed into categories. Exact differences between rank not possible Examples of ordinal level –Mild –Moderate –Severe

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Interval Level of Measurement Third level of measurement Data can be rank ordered and placed into categories. Distance between ranks can be measured. Actual numbers on a scale

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Interval Level of Measurement Examples of interval level –Body temperature –Weight

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Ratio Level of Measurement Highest level of measurement Data is categorized and ranked. Distance between ranks is “true” or natural zero. Zero means a total absence of quantity measured.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Ratio Level of Measurement Debate usually exists between interval and ratio level. Examples of ratio level –Money in bank account –Pain of a person

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Three Learning Objective Three Determine The Appropriate Level Of Measurement For Data In Selected Studies

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Appropriate Level of Measurement Precision—interval or ratio Ranked or categorized sufficient—ordinal Categories of data only needed—nominal

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Level of Measurement Considerations Level is appropriate for the type of data desired. Degree of precision that is desired for the study

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Four Learning Objective Four Recall Questions To Be Answered In The Data-Collection Process

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Data Collection Questions Acronym: WWWWH –Who? –When? –Where? –What? –How?

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Who Will Collect the Data? Researcher is the only person. Team of members Consistency of data collection

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy When Will the Data Be Collected? Data collection time –Month –Day –Hour Time period for data collection usually requires a trial run of the procedure.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Where Will the Data Be Collected? Setting for data collection Optimum conditions are considered.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy What Data Will Be Collected? Type of data needed for the study Examples are data to measure –Knowledge –Attitudes –Behaviors

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy How Will the Data Be Collected? Research instrument Major decision for the study Examples –Questionnaire –Interview

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Five Learning Objective Five Identify Data-Collection Methods

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Data Collection Factors Research question(s) or hypothesis or hypotheses Design of the study Amount of knowledge available about the variable(s)

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Data-Collection Methods Self-report questionnaires Interviews Physiological measures Attitude scales Psychological tests Observational methods

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Variety of Data-Collection Methods More than one method used Similar results from variety of methods –Greater confidence in study findings

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Six Learning Objective Six Discuss The Selection Of A Data- Collection Instrument

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Selection of a Data-Collection Instrument Conduct a literature review Determine measurements of the instrument –Reliability –Validity

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Sources for Existing Research Instruments Mental Measurement Yearbooks (MMYs) Instruments for Clinical Health-Care Research Measurement of Nursing Outcomes Many existing instruments are copyrighted, so permission from holder is required for use.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Development of New Instrument(s) Challenging task Constructing the instrument or revision of an existing instrument Performing a pilot study Considering time, cost, and availability for pilot

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Seven Learning Objective Seven List Criteria For Selection Of A Data-Collection Instrument

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Data-Collection Criteria Practicality Reliability Validity

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Practicality of the Instrument Cost Appropriateness Questions to consider Practicality before reliability or validity

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Reliability of an Instrument Consistency and stability Degree of reliability determined by correlational procedures Types of reliability –Stability reliability –Equivalence reliability –Internal reliability

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Validity of an Instrument Quantity of variable of interest can be calculated with use of instrument. Greater validity, more confidence in instrument Ways to measure validity –Panel of experts –Examination of literature Statistical measurement may be used for correlational procedures.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Eight Learning Objective Eight Compare And Contrast Three Types of Reliability

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Three Types of Reliability Stability Equivalence Internal consistency

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Stability Reliability of Instrument Consistency over time Stability and accuracy Ways to measure –Physiological instruments—stable and accurate –Questionnaire instruments—test and retesting –High correlation coefficient—close to 1.00

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Equivalence Reliability of Instrument Alternate or parallel forms of reliability –The degree to which two different forms of instrument obtain the same results Interrater or interobserver reliability –The degree to which two or more observers use the same instrument to obtain the same results

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Equivalence Reliability of Instrument (cont’d) High correlation coefficient—close to 1.00 –Higher confidence that the two forms of the test are gathering the same information

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Internal Consistency Reliability Individual items measure the same variable. One concept or construct (i.e., variable) is measured. Sample of items is its main consideration. Split-half procedures Coefficient alpha (α) or Cronbach’s alpha

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Nine Learning Objective Nine Compare And Contrast Four Types Of Validity

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Validity Face Content Criterion Construct

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Face Validity Appears to measure what it is supposed to measure Experts review the instrument to validate it. Use of the instrument with people with characteristics similar to study

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Content Validity Items represent the content. Ways to measure –Comparison with literature –Panel of experts in subject area –Test blueprint designed for content and level

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Criterion Validity Scores are correlated with external criterion. Two types of criterion validity –Concurrent validity –Predictive validity

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Two Types of Criterion Validity Concurrent validity –Comparison to other behavior –Correlation coefficient closer to 1.00 means higher validity. Predictive validity –Prediction of behavior in future

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Construct Validity Most difficult to measure Does the instrument measure the construct it is supposed to measure? Ways to measure –Known-groups procedure –Factor analysis

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Known-Groups Procedure Estimates construct through analysis of degree of validity –Measure separate groups –Measure groups predicted to vary on the characteristic(s)

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Known-Groups Procedure Factor analysis –Used to identify clusters of related items on an instrument or scale –Determines if tool is measuring only one or more constructs –Correlational procedures used

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Reliability and Validity Close association Reliability a condition for validity An instrument cannot be valid unless it is reliable. Reliability tells nothing about degree of validity. An instrument can be very reliable but with low validity.

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Ten Learning Objective Ten Explain Four Sources Of Error That May Occur In Data Collection

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Sources of Error All research contains some error. –Human beings –Environment or setting

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Sources of Error Types of sources of error –Instrument inadequacies –Instrument administration biases –Environment variations during collection of data –Temporary subject characteristics during the collection of data

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Learning Objective Eleven Learning Objective Eleven Critique The Data-Collection Section Of Research Reports

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Critiquing the Data Collection Process Find the section in which measurement and collection of data are reported Determine if the level of measurement is appropriate See if the instruments are described clearly and thoroughly Check to see if a pilot study was performed

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Questions for Critiquing Data-Collection Process Did the research report provide information on data collected? –What data were collected? –How were data collected? –Who collected the data? –Where were data collected? –When were data collected?

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Questions for Critiquing Data-Collection Process (cont’d) Was an appropriate level of measurement used? Was there a section in which the instruments are described? Was the description of the instruments thorough? Had the instruments been used previously?

Copyright ©2012 by Pearson Education, Inc. All rights reserved. Foundations of Nursing Research, Sixth Edition Rose Marie Nieswiadomy Questions for Critiquing Data-Collection Process (cont’d) Had the instruments been tested for reliability? If so, what type of reliability was assessed? Had the instruments been tested for validity? What type of validity was assessed? Was a pilot study conducted using the instruments?