Threats to Internal Validity

The following are common threats to internal validity.  If you would like a recap over internal vs. external validity, visit this link. 

Resources:  Cooper J.O, Heron T.E, Heward W.L. Applied behavior analysis (2nd ed.) Upper Saddle River, NJ: Pearson; 2007.

Test Tuesday

Given the following example, what would be the most appropriate response.  You are a BCBA that is well-trained and experienced with toilet-training and feeding disorders.  Most of your clients are referred to you for these reasons.  However, a client's mother has just contacted you to help with her son that has severe self-injurious behavior.  She insists that they have tried all antecedent modifications and reinforcement procedures, and she insists that a punishment procedure be implemented.  What would be the FIRST thing you would do.

1.  Refer the client to another BCBA that specializes in self-injurious behavior. 

2.  Read books, do research, and speak to others in the field to educate yourself on self-injurious behaviors, but in the mean time start procedures based on your research and recommendations from others. 

3.  Put in a punishment procedure because a punishment procedure can be implemented once all alternatives have been tried. 

4.  Conduct your own FA's and determine the function of the problem behavior to determine which procedure would be most effective.

1. Refer the client to another BCBA that specializes in self-injurious behavior. 

In this situation, with little experience in other areas besides toilet-training and feeding, it is unethical to begin treatment.  However, you can refer the client to another BCBA for their SIB behavior, and in the mean time you can educate yourself on the client's SIB.  You can read research, consult with other BCBA's that specialize in the field, and you can educate yourself on the the SIB.  Once you are educated, you can begin working with the client, but in the mean time the client should be receiving services from another certified behavior analyst in the field.

Internal vs. External Validity

What is internal validity?

Extent to which the experiment shows the changes in the behavior are due to the independent variable and not the result of uncontrolled or confounding variables 

Examples of confounding variables:  

-Starting medication

-Change in home life (divorce, death, new baby, move, etc)

-Change in school/therapy life (new therapists, clinicians, new building, new school, etc.)

What is external validity?

The degree to which a study's findings have generality to other subjects, settings, and/or behaviors

-Will this study prove effective if a different population of participants is used?

-Will this study be effective if used with a different type of behaviors?

If the study was done in a clinic, will it be effective if conducted in a school classroom setting?  What about in a home environment?

Resources:  Cooper J.O, Heron T.E, Heward W.L. Applied behavior analysis (2nd ed.) Upper Saddle River, NJ: Pearson; 2007.

Test Tuesday

Which of the following is not a component of informed consent?

1.  The ability to express his or her choices

2.  Voluntary Decision

3.  All potential risks and benefits of the planned procedure must be given

4.  Once the treatment has started, they are not able to refuse the treatment.

4.  Once the treatment has started, they are not able to refuse the treatment.

Due to the knowledge of treatment, the client has the right to refuse continued treatment at ANY time.  

Testing a Definition

So now that you have learned the characteristics of a good definition, how do you test to see if your definition is actually good?

Cooper, Heron, and Heward describe a few questions and answers to determine if you have a good definition.

1.  Can you count the number of occurrences?

-You should be able to answer "Yes"

2.  Will a stranger know what to look for based on the definition alone?

-You should be able to answer "Yes"

3.  Can you break the target behavior down to smaller,  more specific components?

-You should answer "No"

-The target behavior should already be broken down into the most specific components as possible

Resources:  Cooper J.O, Heron T.E, Heward W.L. Applied behavior analysis (2nd ed.) Upper Saddle River, NJ: Pearson; 2007.

Characteristics of Good Definitions

So, you here all the time that you need to write good, clear definitions when defining target behaviors.  For example, you would not just define a target behavior as "hitting" because what one person might score as hitting, another person might not. 

Therefore, it is VERY important that you learn how to write good definitions.

So, what are the characteristics of good definitions?

Objective

The definition should only refer to events that are observable.  

For example:  You cannot say that the client has to be "sad" or appear "angry" when hitting for it to be scored as hitting.  However, you can say that the client has a negative affect, it is paired with crying, etc.  All of the events have to be observable.

Objective=Observable

Clear

It has to be readable and unambiguous.

There should not be any questions.  For example, if you are writing a definition for eloping, you should put how many feet the client has to leave the area for it to be scored as eloping.  Otherwise, the therapist might have many questions about what is considered eloping

Clear=unambiguous

Complete

Precise and concise definitions

Complete=precise

Test Tuesday

Which of the following is not an ethical professional claim that a BCBA or BCaBA should make:

1.  I have had success working with children like your daughter.

2.  I have experience working with children like your daughter.

3.  I am certain that I am able to help your daughter.

4.  Give me 6 months and your daughter will be a new child.  

I tricked ya!  There are two answers.  You should never say both of the following:

3.  I am certain that I am able to help your daughter.

4.  Give me 6 months and your daughter will be a new child.  

You want to make sure that you do not make professional claims such as those above due to the BACB ethical guidelines.  Review the guidelines at the following link.

http://www.bacb.com/index.php?page=100165#guidelines