Appraisal in Counseling Session 2

Schedule Finish History Finish History Statistical Concepts Statistical Concepts Scales of measurement Scales of measurement Norm-referenced versus Criterion- referenced instruments Norm-referenced versus Criterion- referenced instruments Measures of Central Tendency Measures of Central Tendency The Normal Curve The Normal Curve Measures of Variability Measures of Variability Types of Scores Types of Scores

Statistics in Appraisal 1. A language, communication, from one professional to another. 2. How much confidence can I put in this instrument’s scores? 3. Will I consistently get the same scores every time I administer the instrument? 4. Do the scores really measure the concept or construct I want to measure? 5. What can this instrument tell us? What can it not tell us? 6. What is the meaning of the score(s)? Compared to…? 7. How can scores be explained?

Assessment Standards for Educational and Psychological Testing – any method used to measure characteristics of people, programs or objects. Standards for Educational and Psychological Testing – any method used to measure characteristics of people, programs or objects. Anastasi & Urbina– objective, standardized measure of a sample of behavior Anastasi & Urbina– objective, standardized measure of a sample of behavior Cronbach – systematic procedure for observing behavior and describing it with the aid of numerical scales or fixed categories. Cronbach – systematic procedure for observing behavior and describing it with the aid of numerical scales or fixed categories.

Samples of Behavior Usually measuring constructs such as intelligence, interest, etc. which cannot be measured directly. Usually measuring constructs such as intelligence, interest, etc. which cannot be measured directly. Since only samples are gathered must determine if sample is how person usually acts and are inferences we are making correct. Since only samples are gathered must determine if sample is how person usually acts and are inferences we are making correct. Use objective, standardized and systematic measures to gather samples. Use objective, standardized and systematic measures to gather samples.

Assessment Integral to Counseling Assessing client problems. Assessing client problems. Conceptualizing and defining client problems Conceptualizing and defining client problems Selecting and implementing effective treatment Selecting and implementing effective treatment Evaluating counseling. Evaluating counseling.

Benefits of Using Testing Aids focusing on developmental issues Aids focusing on developmental issues Aids problem solving Aids problem solving Helps decision making Helps decision making Psychoeducational tools Psychoeducational tools Data indicate about 73% of counselors responded tests very important or important; only 9% said never used.

Minimum Competency for Proper Test Use Proper testing environment Examinee follows directions so test scores are accurate Examinee follows directions so test scores are accurate Avoid coaching or training Avoid coaching or training Scoring errors Avoid scoring & recording errors Avoid scoring & recording errors Keep scoring keys & test materials secure Keep scoring keys & test materials secure Know your instrument’s psychometric properties Know your instrument’s psychometric properties Counseling and interpretation Establish rapport Know the instrument and the construct completely Willing to interpret & offer guidance Avoid labeling people on basis of test scores Careful about assuming norms for one group apply to other groups Do your homework

Statistics Scales of Measurement Scales of Measurement Nominal Nominal Ordinal Ordinal Interval Interval Ration Ration

Nominal categories, not ranked categories, not ranked manipulating the numbers arithmetically makes no sense manipulating the numbers arithmetically makes no sense Example: Continent of Birth Example: Continent of Birth 1 Asia 2 Africa 3 Europe 4 Latin America 5 North America … What is the arithmetic mean? Continent of Birth Continent Frequency%Cumulative % Asia Africa Europe Middle East Latin America North America US America Caribbean New Zealand Total

Frequency Distribution

Ordinal categories in rank order categories in rank order manipulating the numbers arithmetically may not make sense. manipulating the numbers arithmetically may not make sense. Example Opinions…Likert-like scale Example Opinions…Likert-like scale Median, Mode, Range, Percentile. Not the arithmetic mean Median, Mode, Range, Percentile. Not the arithmetic mean Instructions: Please mark the number from the scale that best corresponds to your answer StronglyDisagree Agree Strongly DisagreeSomewhat Somewhat Agree I think of myself as being U.S. American

Ordinal Data US Ident 1 N=233 Code FreqPercentCumulative Percent Code FreqPercentCumulative Percent Total Total Missing1.4 Total Median Strongly Disagree Mode1.00Strongly Disagree Minimum1.00Strongly Disagree Maximum4.00Strongly Agree Range 4.00 (Max-Min)+1

Interval/Ratio Data Interval and ratio are similar Interval and ratio are similar continuous variable continuous variable can be represented numerically can be represented numerically Mean, median, mode, frequency, range, percentage, percentile Mean, median, mode, frequency, range, percentage, percentile Interval Interval may not make sense when we talk about ratio may not make sense when we talk about ratio for instance…IQ…..is someone who has an IQ of 50 half as intelligent as someone with an IQ of 100? Or does a zero IQ mean an absence of intelligence? for instance…IQ…..is someone who has an IQ of 50 half as intelligent as someone with an IQ of 100? Or does a zero IQ mean an absence of intelligence? Examples: IQ or scores on an achievement test or the GRE, MAT, SAT Examples: IQ or scores on an achievement test or the GRE, MAT, SAT Ratio Ratio continuous data with true zeros. continuous data with true zeros. Height, weight, age Height, weight, age

Norm referenced vs. Criterion referenced

Measures of Central Tendency Mode Mode Median Median Mean Mean

Measures of Central Tendency Mode Mode is the most frequent score is the most frequent score can describe multimodal curves can describe multimodal curves least stable of the measures because it is not readily repeatable least stable of the measures because it is not readily repeatable it is affected by the number of people taking the test it is affected by the number of people taking the test not affected by extreme scores not affected by extreme scores NOIR NOIR

Measures of Central Tendency Median Median middle score achieved middle score achieved 50% of the scores are higher than this score and 50% are lower than this score. 50% of the scores are higher than this score and 50% are lower than this score. If there is no middle, we create it. If there is no middle, we create it. The median can tell us more about data which is skewed versus data which is “normal” The median can tell us more about data which is skewed versus data which is “normal” It is not effected by extreme scores It is not effected by extreme scores No indication of multimodalness. No indication of multimodalness. IR IR

Measures of Central Tendency Mean Mean algebraic arithmetic average algebraic arithmetic average sum of the scores/number of observations sum of the scores/number of observations it is affected by extreme scores it is affected by extreme scores most frequently used Measure because it lends itself readily to more complex manipulations. most frequently used Measure because it lends itself readily to more complex manipulations. Used most extensively to describe normal distributions. Used most extensively to describe normal distributions. NOIR NOIR

Variability

Measures of Dispersion Measure of the spread of scores Measure of the spread of scores Range Range The range is the highest score minus the lowest score plus 1. The range is the highest score minus the lowest score plus 1. Variance Variance How widely spread are the scores from the mean How widely spread are the scores from the mean Standard Deviation Standard Deviation Takes the variance and standardizes it so that the standard deviation is described in the same units as the original scores. Takes the variance and standardizes it so that the standard deviation is described in the same units as the original scores.