Discrimination Trials: Extremely Important in Special Education Instruction

Discrimination training is concerned with the way training stimuli and prompts are presented, as well as the manner in which prompts are faded and removed. For example, if the child has learned to match, select, name a red block “Red,” and a blue block “Blue,” the child has learned to discriminate the colors red and blue.

Some skills are complex and may require an elaborate discrimination training procedure involving many steps and a high number of training trials, whereas other skills are easier for the child to learn and might be effectively taught in considerably fewer trials. The teacher or therapist must always seek to use the discrimination training procedure that leads to mastery most quickly.

Discrimination Trials are very important when teaching new skills. This week I found myself communicating with a team of educators/therapists and independent service providers regarding this subject.

My communication with a student’s assistant: Caleb and I worked on the typing issues. He is not discriminating between, “type”, “spell”, and “read”. He is unsure of his role when asked to do one of these with the laptop in front of him. Think about it this way, the laptop is a signal that he is going to be typing something; however, if the laptop is in front of him and you simply ask him to “read” or “spell” a word he is lost. Make sure you are using the terms in the correct manner. When you want him to type something on the laptop say, “type” (to communicate he is actually going to be typing), if you want him to spell something (this means he verbally spells it) use “spell”, if you want him to read a word (verbally say it) use “read”. Do not use “spell” for typing something on the laptop. We will introduce this later. First, we need to get him discriminating between the three terms. I want you to take data on using this discrimination trial using his weekly spelling words. Remember, you are not collecting data on spelling the word correctly. You are taking data on his ability to execute the task you have cued. If you say “type zip” and he types it on the keyboard, score with a (+). If you say “type zip” and he says, “z…i…p…”, you will score with a (-).

Another example of a discrimination trial that is extremely helpful for students with complex communication needs is Ask vs Tell.

Ask vs. Tell

SD:       “Ask …..”

            “Tell me …”

SR: The student responds by asking or telling you information about a specified subject.


Teacher/Therapist: “Ask my name.”

Student: “What is your name?”

Teacher/Therapist: Answer the question and reinforce by reinterating and identifying what the student did correctly.

Example: “My name is Jenn. Great job asking my name!”

Teacher/Therapist: “Tell me your name.”

Student: “My name is Fred.”

Teacher/Therapist: Reinforce the correct response.

Example: “Awesome! Thanks for telling me your name!”

Prompting: Verbal, Visual

Note: Make sure that you are interchanging “Ask” and “Tell”!  You do not want to establish a pattern.  For example, do not simply require “Ask”, “Tell”, “Ask”, “Tell”…

Check out the following Boom Card digital task card decks with discrimination drills built in.


Lovaas, O. I. (1977). The autistic child: Language development through behavior modification. New York: Irvington.Lovaas, O. I. (1987).

Behavioral treatment and normal intellectual and educational functioning in autistic chil-dren. Journal of Consulting and Clinical Psychology, 55, 3–9.

Lovaas, O. I. (2003). Teaching individuals with develop-mental delays: Basic intervention techniques. Austin: Pro-Ed

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