Finding the full text of tests, instruments, and measures can be very tricky because most well-known tests are only available commercially (i.e.must be purchased). Commercially available tests are often referred to as "published" tests.
The APA has a guide for Finding Information About Psychological Tests that provides an extensive overview of this topic.
Here are a few library resources that you can use to find descriptions of tools or studies discussing how resources are used in experiments.
During the Spring 2021 semester, the library has access to the APA PsycTest database. APA PsycTest includes thousands of research instruments and their psychometric properties. There are more than 61,000 records in APA PsycTests, many of which are PDF copies of unpublished tests developed by researchers. You can watch the video below for some tips on searching for full-text tests and requesting permission to use items found on APA PsycTest.
APA PsycINFO has a Tests & Measures field, which can be use to look up information related to psychological tests and measures. Many of these tests are not available in the full text, however you can find articles about how they have been applied in research studies. To learn more about using the Test & Measures field in APA PsycINFO, you can check out this video:
You can also check out these additional databases for examples of tests and measures, as well as databases of articles that include experimental studies using specific test: