The Question: How would I know if my research is one or two tailed and what are the responses below considering that the data I have seems like a a within subject thing?

Your speed in correct trials congruent: 1137 ms incongruent: 1249 ms Your Stroop effect is incongruent minus congruent: 112 mse. Is the research hypothesis one tailed or two tailed? f. State the research hypothesis. g. State the null hypothesis. h. What is the experimental design of this study? (between subjects or within subjects)\f\f\f\f