To match the research methods in Set-I with the appropriate data collection tools in Set-II, we need to understand the characteristics and typical use of each method.

1. Experimental Method: This research method is used to determine causation by manipulating variables and observing the effects. A common data collection tool associated with the experimental method is standardized tests. Standardized tests provide controlled conditions and measures necessary for experimentation.
2. Ex post-facto Method: This method involves studying an event after it has already occurred and looking at past data to understand causes or consequences. A typical data collection tool here is typical characteristic tests, as these help in analyzing traits or behaviors that were influential in the outcomes.
3. Descriptive Survey Method: This approach involves collecting data to describe characteristics of a population or phenomenon. The most common tool used is a questionnaire, which allows for the collection of large amounts of data systematically and efficiently.
4. Historical Method: Focused on examining past events, the historical method often uses primary and secondary sources, such as documents, records, and archives, to interpret and understand historical events and trends.

Based on the explanation above, the correct matching is:

• a-iii: Experimental method - Standardized tests
• b-iv: Ex post-facto method - Typical characteristic tests
• c-ii: Descriptive survey method - Questionnaire
• d-i: Historical method - Using primary and secondary sources

Therefore, the correct answer is a-iii, b-iv, c-ii, d-i.