Piece n. 1. a part of a whole 2. an individual member of a unit 3. an unspecified distance 4. a literary, journalistic, artistic, dramatic, or musical composition

It could be inferred that the word pieces in the paragraph mean "parts."

According to behaviorism, instruction should provide necessary stimulus in order for learners to produce desired response. it is important that the learner must know how to execute the proper response under the required conditions in order to produce the desired response (ertmer & newby, 1993). instruction should provide learner with opportunities that the learner practice to elicit the desired outcome.