Boundary-of-Meaning (BoM) of a Target Statement (TS) is a good measure of the depth of understanding in a given knowledge domain. It documents the results of comparing TS to other representations by two different criteria:
MERLO is a multi-dimensional database that allows the sorting and mapping of important concepts in a given knowledge domain through multi-semiotic representations in multiple sign systems, including: exemplary target statements of particular conceptual situations, and relevant other statements.
Figure 1 is a template for constructing an item family of MERLO assessment items anchored in a single target statement TS. Collectively, MERLO item families encode the conceptual mapping that covers the full content of a course - a particular content area within a discipline, for example ‘calculus’ in mathematics (Figure 2).
Issues, Controversies, Problems
MERLO pedagogy guides sequential teaching/learning episodes in a course by focusing learners’ attention on meaning. The format of a MERLO assessment item allows the instructor to assess deep comprehension of conceptual content by eliciting responses that signal learners’ ability to recognize, and to produce, multiple representations, in multiple sign-systems - namely, multi-semiotic - that share equivalence-of-meaning.
A typical MERLO assessment item contains 5 unmarked statements: unmarked TS (target statement); plus four additional (unmarked) statements A B C D E from quadrants Q2; Q3; and Q4. Our experience has shown that inclusion of statements from quadrant Q1 makes a MERLO item too easy, because it gives away the shared meaning due to the valence-match between surface similarity and meaning equivalence - a strong indicator of shared meaning between a Q1 and TS. Therefore, Q1 statements are excluded from MERLO assessment items.
Task instructions for MERLO assessment are:
At least two out of these five statements – but possibly more than two – share equivalence-of-meaning.
Figure 2. is an example of MERLO assessment item used at Independent Learning Center (ILC) of TVOntario, a distance education/e-learning high school. The MERLO database for grades 11-12 calculus course was developed by master mathematics teachers who participated in a workshop ‘Learning in the Digital Age with Meaning Equivalence Reusable Learning Objects (MERLO) and Interactive Concept Discovery (InCoD)’ in 2006-2007, following detailed concept mapping. It is a multi-semiotic MERLO item in the following sign systems: symbolic mathematical equations A and E; visualization/diagram B; language and symbolic mathematical equations C and D.
Figure 3. Example of a multi-semiotic MERLO item (history of architecture)
Figure 3 is an example of a MERLO item in 2nd year course on history of architecture at Ryerson University. It includes 5 representations (at least two of which share equivalence-of-meaning), in the following sign-systems: urban plan A; photograph B; orthogonal drawing C; language D; 3D sketch E.
Learner’s response to a MERLO item combines two formats: (i) multiple-choice/multiple-response (recognition) format; and (ii) short answer (production). Subsequently, there are two scores for each MERLO item: recognition score; and production score.