Scoring and Interpreting Results

Purpose of Scoring

• transform observed or self-reported performance on a test into an accurate, meaningful, and defensible interpretation

  • determines need for services, areas for intervention, discharge, and reflect change in performance over time

Norm Reference

compare to group of individuals

• multiple

• local

• national

• special

Criterion Reference

compare clients score to mastery of performance

Important things to consider about scoring

• scale used for measuring on a test (NOIR)

• types of scores obtained

• distribution of scores

• descriptive info gained throughout the assessment

Levels of Measurement

• nominal (category)

• ordinal (ranked)

• interval (=distance, no true 0)

• ratio (= distance, true 0) best type

Types of Scoring

• hand scoring: most common, manually calculate scors

• computer-based: item info is entered into website or downloaded software and scored automatically

• computer adaptive: responsive to input. if you get one wrong, give 3 more tries

Central tendency

• typical value for a distribution or the center of a distribution

  • mean: interval/ratio

  • median: ordinal

  • mode: nominal/ordinal

Obtained scores come from

raw data

Standard Scores

• score that allows for equal comparison of performance across various assessments

• used on total scores

  • Z score: tells you how far away from the mean the client is

  • T score: uses a mean of 50 and SD of 100 converting it to a 0-100 scale and is interpreted like a percentile

Scaled scores

• similar to standard scores in that it allows us to compare a clients performance to others and across tests

• does not follow a normal distribution

• used on subtests

Percentile

• cumulative percentage score used with norm-referenced tests

• indicates the % of people who scored above and below the client

• is the area under the normal curve

Percentile Ranks

• explains the relative standing of the client among members of the normative group

• ranks are according to 100

• ex. 80th percentile rank → 80th out of 100 people

Stanine

• standard scores are on a nine-point scale and convert scores into a meaningful single digit to compare

• lacks precision of percentile

  • uses 9 point scale with 5 being the mean, and an SD of 2

Grade Equivalents

intended to represent individuals abilities according to a grade level

• not always useful as not every grade is the same across schools

Developmental Age/Age Equivalents

intended to represent a persons abilities according to a developmental stage

Cut-off scores

specific score ranges that indicate the potential presence or absence of a disease, condition, or impairment

• best to use standard scores for cutoffs

Obligations of Scoring

• must use exact scoring procedures

• use appendices to convert scores from the raw score to obtained/derived scores

• interpret scores and link them to occupation

• share the results in a clear language to ensure the client and/or caregiver understands what the scores indicate using OTPF-4 language