In the context of reinforcement theory, with , consequences follow a behavior after different times, some shorter and some longer, that vary around a specified average time.

Variable interval

Explanation:

In a variable interval, the researcher will not give the reinforcement on a regular schedule.

The purpose of this type of reinforcement is to condition the subjects to adopt a certain behavior even after the reinforcement is taken away in the future.

Example:

Let's say you want to teach your son to put away his toy after he's done playing it.

In order to encourage him, you give him his favorite candy as soon as he's putting away his toy, but you do not give the candy every time he does it. Sometimes you give it, sometimes you don't.

When this happen, your son will start to develop an understanding that there is always a possibility for candy every time he put away his toy.

This will make him more likely to put the toy away and wouldn't sulk even after he does not receive the candy.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.