Quantitative data is stronger. Quantitative is objective and qualitative is subjective. For instance with the olympics Swimming is quantitative based on hard numbers of time. Diving is qualitative the point system is subjective it's based on someone's interpretation of the performance. This is why they have more than one judge and people more frequently feel they have room to protest their scoring. You see far less debate in swimming results.
In general, quantitative data is stronger. Qualitative data tells you what. For example, a list of ingredients in a cake (e.g., sugar, flour, etc.) is qualitative data. Quantitative data tells you both what and how much. For example, a list of ingredients in a cake along with the quantity of each ingredient that was used (e.g., 2 cups sugar, 4 cups flour, etc.) is quantitative data).