Phuong is conducting an experiment on proofreading. all participants are asked to read a passage with several typos and correct the errors. however, one group proofreads by reading silently, a second group proofreads by reading aloud, and a third group proofreads by reading the passage silently backward. the researcher calculates the average number of errors found in each group and finds that both the reading silently and reading aloud groups found more errors than the reading silently backward group. what are the variables in this study?

type of proofreading and number of errors found

Explanation:

Before starting an experimental research process it is necessary to define the dependent and independent variables. These are the variables that will guide how the result of the experiment should be evaluated and the conclusion of the work.

Dependent variables are those we want to study to see the effects of changes on independent variables. These variables measure the effect of treatments and are often a measurable variable. In the experiment shown in the question above, the dependent variable is "number of errors found".

Independent variables are all those that can be manipulated or controlled, have an effect on dependent variables, and usually cannot be measured. In the case of the experiment shown above, the independent variable is "type of proofreading".

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.

answer; lorenz;