What type of data do you use to make decisionsin your classroom?

As an elementary school teacher, this question makes me sweat. Although I use many different types of assessment strategies, the word "data" reminds me of a high-tech, computer analysis program of numbers. I do not use only data to assess my children. Having to teach 6 differentiated subjects a day, I find that one type of assessment (ie. data based) does not fit all situations.
Perhaps I could include rubrics as a type of data. I suppose tests and quizzes would also be type of data collection. We do have quarterly assessments in math, reading, and science where data is collected as well. But, these are not the only ways for me to drive instruction in my classroom. I also use teacher observations through oral assessments and classroom participation.
However, all too often it seems that once data is collected, the time to teach that particular skill has passed as there are many other skills to be taught. Pacing charts and differentiated classrooms do not allow for much extra time. I do not deal with a class of English college prep students and then our English honors class comes in for the next lesson. In reality, I deal with one third grade class that has an educational range from first to fifth grade. Data collection simply gives me an idea of who gets it and who doesn't.
Of course I will pick and choose those topics that are of most importance to review either in whole group or small group situations, but trying to collect multiple strategies over multiple subjects, and implement them into individualized lessons in order to stress a skill is nearly impossible for one teacher to accomplish.
I guess if I really think about it, the data I collect in the classroom helps to support me in decisions I make for the placement of a child. It's the "facts" that support me as a teacher when I say that a child is struggling a great deal and needs extra support from the school. It's the proof that shows a child is not understanding grade level appropriate material. This information helps me to make modifications to a curriculum for certain students, as well as challenge children that can handle a harder work load. Simply put, data helps me instruct a students by telling me what they can handle.