Measurement is trustworthy when the degree to which repeating a measurement procedure under the same conditions produces the same result.

When observers collecting data have a shift/drift in how they interpret the operational definition of the target behavior that affects the validity of their data.

When an observer’s data collection or performance is influenced by the awareness that they are being monitored and evaluated.

Data that represents an unwarranted and misleading picture of behavior because of how it was measured, typically a product of time-sampling, limiting measurement scales, or poorly scheduled measurement periods.

When an observer’s measurement is influenced by an expectation or belief they hold rather than what actually occurred.

A measurement of the degree to which two or more observers report the same values when observing and collecting data for the same behaviors/events.

PTB founder Dana Meller helps connect each of the validities to the validity of this explanation.

PTB co-founder takes some of the fear out of the interobserver agreement math with simple tips that can help narrow your discrimination.

PTB co-founder goes into the three factors that define trustworthy measurement-- "validity", "reliability" and "accuracy". But what's the difference between each? Dana explains.

It's particularly meaningful to be able to tell validity, social validity, internal and external validity apart. PTB co-founder Dana Meller has some tips to do just that.

Refers to the changes in an individual’s behavior due to the presence of an observer.

The degree to which what was measured (observed value) is representative of what actually occurred (true value); in other words, the data was measured correctly.

PTB co-founder Dana Meller discusses Interobserver Agreement (IOA) and its significance in behavior analysis. Discover the desired percentage of agreement for IOA and its role in increasing data credibility and evaluating intervention effectiveness. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

What are the three indicators of trustworthy measurement in ABA? PTB co-founder Dana Meller explains and why they ensure data accuracy and reliability. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Test your Measurement, Data Display, and Interpretation skills with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about several #interobserveragreement (IOA) facts, with rules to live by. Here, Dana highlights a variety of important IOA benefits, as well as IOA percentage of agreement criteria details and the different reporting options. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Math can be daunting, but practice can help. You don’t have to be a math whiz to master the Interobserver Agreement formulas. Get more practice and gain confidence with the PTB IOA Mini Quiz. Updated for the 6th Edition Test Content Outline, the PTB IOA Mini Quiz features a new interactive format that simulates the test experience. Thirty fill-in-the-blank questions cover all 9 IOA formulas. Optional hints included with each quiz question assist you with the correct formula along the way. Check your work and collect data on your performance with the detailed score report. 

Test your knowledge with PTB co-founder Dana Meller as she explains the specific indicator of trustworthy measurement that corresponds with repeated measurement yielding the same result. Included is a description of all three indicators of trustworthy measurement validity, accuracy, and reliability. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Test your knowledge of measurement confounds with PTB co-founder Dana Meller as she discusses one of the four types of threats to internal validity, with corresponding examples. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Sharpen your measurement skills with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about IOA and helps explain the different formulas used for time sampling measurements. Dana covers four IOA formulas: Interval-by-Interval, Scored Interval, Trial-by-Tial, and Unscored Interval; and highlights key considerations and pitfalls associated with each. BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Test your measurement knowledge with PTB co-founder Dana Meller as she reviews a BCBA® mock exam question about the key indicators of trustworthy measurement, revealing the most significant threat facing accuracy and reliability. Dana provides insight into the distinctions between reliability, validity, and accuracy and how they relate to measurement. BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.

Test your knowledge of measurement procedures with PTB co-founder Dana Meller as she explains, in detail, one of the threats to validity with several corresponding examples. Dana also shares a clever memorization study tip that will help you on the Big exam. Refer to BCBA® Task List (5th ed.) Section C-8: Evaluate the validity and reliability of measurement procedures.