Well, the test envelope is a reference to the particular question or acquisition of knowledge of a particular area that is being experimented upon or tested. In the scientific method, the first step is to ask aquestion, or formulate what you want to know in the format of a question. This would be considered the test envelope, what we are trying to capture in our testing efforts.
The test points would be the specific items that are being tested, these would include the construction of the experiment with its experimental group and control group, along with the indication of the independent and dependent variables. The specific items that are tested will either provide the information we seek or not; we will determine the "whys and why nots" after the test points have been conducted within the parameter of the experiment.
And finally, the test range would probably be a general listing of minimal achievements to maximal achievements, in terms of experimental result performance. These would be a range of indicators, from lowest to highest, that would be used to measure the effectiveness of the independent variable and its influence on the dependent variables.