Why triangulate?
Triangulation allows students to demonstrate their learning in a variety of ways outside of the traditional products like quizzes, tests, assignments and labs. It validates the understanding that they demonstrate during class and in conversation with their teacher or peers (observed by you). By validating the work students do in class this has also been reducing the question "Is this work marks?" because everything they do in class can be assessed as a demonstration of learning.
Triangulation also gives teachers a broader view of where a student actually in, in their learning journey. One of the things that Peter Liljedhal talks about is using triangulation as a way to determine the most appropriate grade for a student. This is done by looking at the student's understanding demonstrated through products and comparing it to the understanding they demonstrate through conversation - are they consistant? If they do, keep moving, if they don't, use observational assessments to determine which level of understanding is most indicative of the student's true understanding. The fantastic part of this is, it gives students that struggle with products like tests, an opportunity to show you what they really know, and it means students that rely on memorization for quizzes and tests, have to show that same level of understanding in the classroom.
Observational and conversational assessments are also great ways to differentiate your assessments easily and aligns itself with the Growing Success Principle of offering a variety of assessments for each overall expectation.
How to?
The three things that can make the implementation of triangulation of data easier in your classroom is;
a. Identify how you want to record your observational and conversational assessments (Observational and Conversational Trackers).
b. Have an idea of what a level 1, 2, 3 and 4 is for the concepts you are assessing through observation and conversation.
c. Have an idea of how you are going to weave together / weight the different assessments. There are a lot of ideas out there about how to do this, and you need to find what feels right to you, and works with your department and school.
Differentiating Triangulation (from Hastings and Prince Edward District School Board)
This visual shows how different students are able to demonstrate their understanding in different ways, all within the same classroom. Student A's grade is determined with an equal weighting for all three types of assessment, Student B's grade is created with a much heavier weighting on the understanding they demonstrated through conversation and Student C's grade is determined by placing a higher weighting on the observational assessments.