A researcher was interested in the role of caffeine in sports performance. In cooperation with her University's baseball team, she randomly assigned players to one of two conditions: (1) no caffeine or (2) low dose (100mg). She then used performance on a batting machine as a test. She speculated that caffeine would positively affect performance. From the description for each case, state whether: 1. Is the study descriptive, relational, or causal? 2. Is the study cross-sectional or longitudinal? 3. What is (are) the IV (IVS)? 4. What is (are) the DV (DVS)? 5. What are the alternative and null hypotheses?