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Posts Tagged ‘granularity

If I was facilitating an imaginary course on thinking skills, I might use this Q and A in this tweet thread to discuss the concept of granularity. The context for granularity is contact tracing during a pandemic.

The initialisms are SE (SafeEntry) and TT (TraceTogether).

SE is a system of checking individuals in to locations they visit, e.g., workplace, school, mall, park, etc. The checking in can be done by scanning a QR code at the entrance of the location, scanning the bar code of an identity card at an entrance station, or using the SingPass app (which is location-aware and has a QR code scanner).

TT is a newer system that ties the identity, contact information, and movements of an individual to a bluetooth device. This device can be the TT mobile app or a token, the latter of which is being widely distributed now. TT uses bluetooth signals to determine who an individual might have been in close proximity to and for how long.

As explained succinctly in the series of tweets, the two allow for more thorough detection of coronavirus transmissions.

The root of the question was a lack of understanding about the granularity of detection and tracing. SE has course granularity — it relies on people checking in to location, e.g., a building. We might not know exactly where that person was in the building unless they check into smaller rooms in that building.

TT provides finer granularity. As people with the bluetooth devices walk past one another or otherwise position themselves within range of a bluetooth signal, the devices take note of the identity and contact information of people in proximity. This has been the subject of discussions of privacy for some months now, but this is not the focus of my reflection.

We need both coarse and fine granularity for coronavirus contact tracing. We need to know where people were, when they were there, who else was there, and how to contact all involved.

Such granularity also transfers to thinking creatively and critically. Coarse granularity might be compared to big picture, bird’s eye view, or the forest. Fine granularity is akin to details, on-the-ground perspective, and the trees or leaves. We need both to be effective thinkers.

For me reading some Facebook (FB) group posts is like feeding a morbid habit of watching train wrecks.

I can see them coming because they are guaranteed. The conversations (if they can be called that) are unpleasant, but I plow through anyway. Why? All for the single pearl in the mud trampled by swine.

By comparing what I do and read in FB and Twitter, I realise that the issue is granular control. I can choose who I follow on Twitter. I can only choose which groups I join in FB.

I can even block people in Twitter so that I curate the right kind of followers. This is not the same as muting people on FB as the control is finer and deeper in Twitter.

It is strange that the more verbose FB provides less granularity of control while the shorter form Twitter provides more. This starts to make sense if you buy in to this description: FB is where you hang out with family or friends. Twitter is where you learn from strangers. It makes sense to have locks on your front door, but not on the ones inside.

But this is where the description falls apart. FB groups are full of strangers who have a lot to say with very little sense. You need only examine any FB interest group with the lens of granularity to realise how this leads to breadth instead of depth.

By breadth I mean the reach that large FB groups have in transmitting information. By lack of depth I mean unsubstantiated rumour, baseless information, or knowledge built on weak foundations.

Twitter is not immune from these, of course. But you can choose who to follow and you can even choose who follows you. You can go for quality, not just quantity, and by doing so choose depth over breadth. As you reputation grows over time, you might develop reach and breadth.

Developing depth over breadth is a more responsible approach. I wonder if this is modelled and taught in digital and media literacy modules. If this is not, then learners just go with the flow of popularity contests that favour breadth over depth.

In Part 1 of my analysis of the new PSLE assessment system, I highlighted the important fundamental switch from norm-referenced testing to criterion-referenced testing.

In Part 2, I described how the summative design and implementation of the high-stakes exam counters positive change.

In this part, I reflect on MOE’s and the public’s obsession with differentiation when we all should be more concerned about granularity.

The current PSLE uses transformed scores (T-scores) and their aggregates as outcome measures for the exam. There are at least three major problems with doing this.

  • The scores can be normalised (see Part 1) and this process is not transparent to the students or the public.
  • A score might indicate where a student stands relative to his or her peers, but it does not indicate what that number means. The student does not know what areas of learning need to be addressed because the exam papers are not returned and there is no feedback loop. This is typical of summative assessment (see Part 2).
  • The aggregate scores seem to finely differentiate students who are competing for places in Secondary schools. For example, a student with an aggregate score of 221 gets in, but another with 220 does not. Someone sets an entry score, but no one can really explain why that benchmark is and what it means. That is one way we play the cruel numbers game.

PSLE2021 is supposed to take away that differentiation because exam papers are graded with Achievement Levels (ALs). Students are assessed on four academic subjects and each subject can be graded from AL1 to AL8. This results in 29 discrete categories of aggregate AL scores of 4 to 32. There is a better, but still not adequate, granularity of scores.

It is no surprise that other bloggers and their mothers have pointed out that the competition will now be for low aggregate scores. Tuition centres might tweak their marketing material to focus on lowering AL scores.

The schooling arms race used to be to get the highest aggregate T-score possible. The next battle is to get the lowest aggregate AL score possible. This is like a Pokémon Go game, just not as fun. You do not want to collect all the scores. You only want the very rare AL1 Pokémon.

The “new” PSLE does not change or break the summative assessment mould. It is still a sorting tool. With the ordered choice of Secondary schools by students playing a more important role than the current model, it is being tweaked to be a decision-making tool.

If the focus is on student achievement and learning — as claimed by the MOE PSLE2021 microsite and echoed the press — students need even greater granularity. By this I am not referring to exact scores of each paper, although this will provide more coarse insight. I am also referring to feedback and remediation on areas of weakness.

At the risk of painting a overly simplistic dichotomy, we have these divergent paths:

  1. Summative assessment model, T-scores, fine differentiation for the purpose of sorting.
  2. Alternative assessment model, high granularity for the purpose of meaningful learning.

Our MOE seem to be designing a hybrid, at least on paper. In its wish list is: Summative assessment, some granularity, a focus on learning. This is a very elusive Pokémon, it is exists.

What paths will we take? What game will we play? What is at stake?

Granularity by velmc, on Flickr
Creative Commons Attribution-Noncommercial 2.0 Generic License  by  velmc 

Ask just five well-informed people what it means to be learner-centred and you are likely to get different perspectives.

For some, this might mean using instructional strategies that get the learner more involved in the processes of teaching and learning. Examples might include think-pair-share or a jigsaw method. The learning tasks may be problem-based, case-based, scenario-based, game-based, etc.

This is a fine level of granularity. This is the operational detail of being learner-centred.

Zoom all the way out and there is the mindset of focusing on learning and the learner instead of teaching and the teacher. This might manifest itself in experiences instead of lessons, being demand-driven instead of supply-driven, and orienting to more just-in-time instead of only just-in-case instruction.

That is a coarse level of granularity and a philosophical orientation.

You would think that the coarse grain should reveal itself in the finer details. But I have noticed people who claim to be learner-centred but behave otherwise.

Why? It is easier to make claims than to back it up. Theory is not practice. A description is not a prescription. Being well-informed is not the same as being well-practiced.


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