Tutorial-some answers to last week's questions and so on...

Today I took a tutorial class with the same group of students as attended last week's lecture, and got to ask them what they found so difficult, and make sure all of them could do the sums they had so much difficulty with. Since last week's session, they had already had a two-hour tutorial on the subject, and some related lab work. Of the around seventy students, maybe fifty turned up for today's tutorial, and of these, perhaps twenty admitted to still being unable to apply the Mogden formula.

My theory that much of the problem lay in the area of grasping the relevant technical glossary was confirmed, and I consequently went through each of the terms to the full class, using a worked exercise as planned. Not just the terms I identified last week, but more or less every TLA we were using was poorly understood by the audience. (Engineers love TLAs, BTW)

There were plenty of questions from the audience, answered either to the group, or to individuals by a combination of myself and the Prof. (who was in attendance throughout this week). We were still answering questions about water engineering jargon after two and a half hours of the programmed two hour tutorial, at which point I had to leave.

However, after an hour of zero-assumed-prior-knowledge teaching, all of the learners could substitute the right values into a number of formulae. Around the point that I had to leave, they had been given a spoon-fed four-point plan of a way to carry out a second, related calculation required to complete a lab. assignment.

It was quite difficult, but nevertheless compared favourably with carrying out surgery or aircraft design, contrary to pedagogic opinion. I do however find that after a day with a few hours of teaching in it, I feel mentally stimulated to the point of having difficulty sleeping. My mind is turning over the events of the session in an attempt to draw out the lessons which may be learned about the attempt to transfer knowledge.

Which statement implies that my model of teaching is still bucket-filling rather than fire-lighting, contrary to Yeats' aphorism. But of course the opinion of a poet isn't exactly hard evidence.

I could see that a few of yesterday's punters could have done with more "fire", but if your fire isn't lit by the time you are in your twenties and doing a Master's degree, perhaps your wood is just too damp to light. Perhaps you'd better leave the fire alone, and just fill your bucket at the pump. Not everyone can be a fiery poet, nor should they want to be.

Isn't this model in fact partially responsible for the UK's problems? We aren't short of poets, we are short of technicians, and learning to be a technician involves very little little poetry, and a great deal of hard work learning useful, but otherwise unexciting things.

In another blow to the poetry of teaching, my evaluation questionnaire was circulated to the course attendees today. Obviously the results of this will not be as objective a measure of performance as one would get in the hard sciences, but I assume they will be a better measure than my chats with the students, if only because they are to be submitted anonymously. Few people like giving negative feedback to a person's face, but if I don't want to take the negative with the positive, how am I to improve?

First Uni Lecture: Provisional Conclusions

If my seminar yesterday had been a scientific experiment, I'd be redoing it from scratch. At very short notice, I had to radically change the content, and amount of material, leaving some parts of my post-delivery questionnaire irrelevant. Revised room layout and pre-release of teaching material did not happen as desired.

However, I at least managed to provisionally confirm and refine the impressions I had received in my observations so far.

1. Getting students to learn to carry out quite elementary calculations is astonishingly time-consuming.

The combined efforts of myself and a Professor over perhaps 30 minutes were required to get two correct answers from an audience of seventy M.Sc. students to a question which involved substituting values provided into the Mogden Formula:





It's just addition and division! I'll have to speak to my hill-walking partner*, (who teaches maths) about this, but I have a theory. I also found this a little tricky when I first encountered it, and the questions that were being asked yesterday are suggestive of a similar difficulty to the one I had.

The values of Ot and St for substitution are given as COD and SS values, and there is a little confusion around this. I can test this the next time I present this material by working through an example on the board, emphasising the difference in nomenclature.

2. It's hard to predict in advance how many questions you are going to get when you are doing straight lecturing, but there may be a correlation with a student's age and/or whether they are paying for the course.

Yesterday's audience with an average age in the late twenties, and a few students older than me (a similar profile to the audiences I'm used to in the Middle East) asked an average of around one question every two minutes during my two hours of lecturing time. This is even more than I get in the Gulf, and as over there, the questions were quite wide-ranging.

I didn't get much chance to practice Socratic questioning, they were putting me on the spot rather than the other way round. I personally like this, as long as the subject being taught is one like yesterday's where I have a breadth of knowledge.

The audiences of teenagers I have seen during my observations on the other hand ask very few questions, and what questions they do ask are extremely focussed on the exercise in hand.

It's not just them however, one of the mature students did however ask me the classic question "will this be in the exam?" yesterday-In your face, "Deep Learning"!

So what did the students learn? Judging by the questions whose answers seemed to satisfy the questioners:

1. Technical vocabulary, specifically the meaning of terms such as hydraulic retention time, batch and continuous processes, biochemical oxygen demand, etc.

2. Outline details of the available technologies for effluent treatment, especially anaerobic digestion

3. For a minority of the students, how to use the Mogden Formula (but they are being shown how to use it again today, so I was only softening them up, really)

I mainly used traditional lecturing, aided by PowerPoint graphics and hand-drawn illustrations for the bulk of the material, and extemporised on the basis of questions posed by the audience, using examples from my professional experience. The Mogden formula calculation was done on more of tutorial basis.

Going back to Marzano, the emboldened text was addressed:

Knowledge Goals

If the instructional goal is to enhance students’ understanding of vocabulary terms and phrases:

• Provide students with a brief description or informal definition of each word or phrase.

If the instructional goal is to enhance students’ understanding of details:

• Present the details in some form of story or elaborated description.
• Have students represent their understanding of the details in linguistic (e.g., notes, outlines) and nonlinguistic formats (e.g., pictures, semantic maps, charts, etc.).
• If the instructional goal is to enhance students’ understanding of organizing ideas (e.g., concepts, generalizations, principles):
• Demonstrate the organizing ideas to students in concrete terms.
• Have students apply the concept, generalization, or principle to new situations.

If the instructional goal is to enhance students’ ability to perform subject-specific algorithms:

• Present the various steps in the algorithm.
• Have students practice the algorithm paying particular attention to how it might be improved.
• If the instructional goal is to enhance students’ ability to perform subject-specific tactics or processes:
• Present students with general rules or heuristics as opposed to specific steps.
• Have students practice the tactic or process paying particular attention to how it might be improved.

Cognitive Goals

If the goal is to enhance students’ ability to store and retrieve knowledge:

• Provide students with strategies that use the representation of knowledge in nonlinguistic forms (e.g., mental images).

If the goal is to enhance students’ ability to identify similarities and differences, to analyse the reasonableness of new knowledge, to generate inferences about new knowledge, or to apply organizing ideas:

• Provide students with a set of heuristics, as opposed to steps regarding the processes involved.
• Have students practice the heuristics, paying particular attention to how they might be improved.

If the goal is to enhance students’ ability to make decisions, solve problems, or perform investigations:

• Provide students with heuristics for the overall processes of decision-making, problem-solving,and investigation, and have them practice the heuristics, paying particular attention to how they might be improved.
• Provide students with strategies for using what they know about the topics that are the focus of problems, decisions, and investigations.

Self Goals

If the goal is to enhance students’ understanding of and control of their beliefs about self attributes, self and others, the nature of the world, efficacy, or purpose:

• Have students verbalize their thinking relative to these areas.
• Have students make linkages between specific beliefs and specific behaviours in their lives.

A qualified success from the experimental point of view, then.

But of course, experimental considerations are secondary. Effective teaching was the point of the exercise. As far as I know, both client and students are happy, but I am awaiting feedback from both, which may give me information on how I can improve.

*Who comments as follows: "Not all teenagers are bad when it comes to maths. I had a young lady ask me today what the min/max would tell you if you plot the graph of a derivative. Pretty good really as most of them don't want to know what a graph looks like unless it's on the exam. I'll be interested to hear your theory"

-Isms and -ologies

In previous correspondence with James Atherton, I was described as a positivist. Popper's critique of science is an attack on the positivist view, and most arts graduates are under the mistaken impression that Popper's view is definitive. Hence to call someone a positivist is almost a sort of insult, though I'm reasonably sure none was intended.

These -isms and schools of mutual incomprehension are to my mind one of the things which mark a subject whose axioms are false. It's not just pedagogy, or even just arts subjects-mathematically based subjects can be even worse. Not only are they wrong, they are precisely wrong.

Economics has the false assumption of the rational and perfectly informed consumer, which prevents it from predicting the bubbles caused by real, alternately irrationally fearful and exuberant punters.

Theoretical physics has its "porn", where mathematicians pile speculation on top of interesting but groundless assumption, and get themselves nowhere at all. Their masturbatory hypothesising is always untestable, and is therefore not a scientific activity. A fart has more substance than "string theory".

I can't remember who said that the most intractable arguments are between parties who share a common misunderstanding, but that seems to be the root of the problem here. If we start from false axioms we can never resolve those problems which require us to notice that our unquestionable assumptions are false, hence schools of thought evolve which attempt to twist reality one way or the other to suit their own partial view.

Partial is in fact precisely the word for these doctrinaire schools of thought, as they are based on individual preferences, contain only part of the truth, and are biased. The six blind men and the elephant is an old story which illustrates this ancient and all too human flaw. There's nothing novel about dogma.

Does research carried out by Marxist sociologists ever conclude that capitalism has some benefits? No, they are always looking for the proof of Marx's axiomatic ability to predict the future, and the supposedly inevitable collapse of Capitalism under its internal contradictions.

After 150 years, they start to look a bit like the Jehovah's Witnesses, repeatedly rescheduling the rapture. Do they question their axioms? Hell no! They personally identify with their theory, it is not an idea which can be changed in the face of new evidence, but a quasi-religious belief.

It doesn't just affect "Social Science", Marxism actually stood in ideological opposition to both Einstein's theory of relativity and Mendelian inheritance in the old USSR!

I don't think I'm an adherent of any -ism, I'm an Engineer and Scientist. I'm no philosopher. I may be a realist, a pragmatist, perhaps even the pedagogue's dreaded atheoretical empiricist, but these -isms are all provisional. Show me something which works better, and I'll drop them. If anyone thinks I'm wrong in what I write, tell me why, labelling me as being from a particular school of thought which differs from your own is no rational criticism at all.

How deep is "Deep Learning"?

Another observation yesterday, of a group of first-year Chemical Engineering students who were set a multi-day exercise intended to assess their level of engineering understanding, where "understanding" means something slightly more complicated than an ability to regurgitate facts, but not something so mystical that we'd need to call in "John Keating" to interpret it.

Here's how it was explained to the students:

"This is the first opportunity, for you, to demonstrate formally the level of understanding you have gained from the start of the course. The modules you are studying have as their learning outcomes all the statements linked to the,“Understanding the underpinning science and mathematics and its underlying principles”

The week will also allow you to show how you are beginning to move into the engineering space by extending the basic scientific principles into elements of engineering practice ,“Understanding and ability to use relevant materials, equipment, tools, processes or products” and design work, “Students should accumulate portfolios of design work as they progress through a course, starting with closed problems around simple processes up to large scale open ended design “.

The week recognises the importance of transferable skills so the assessment criteria will judge how well you communicate, work as part of a team, use IT, problem solve, deliver presentation and measure the performance of others."

The italicised bits are taken I believe from the I Chem E's requirements for accredited Chemical Engineering courses. So the exercise is intended to measure some things which those interested in obfuscation might argue are unmeasurable. However, my experience yesterday suggested that approximate measurement of such matters would seem to fall squarely under the heading of what James Atherton has previously called the bleedin' obvious.

Why do I say this? Because my independent impression of how well eight groups of students fared relatively in the exercise was identical to that of the other lecturers and lab supervisors. This therefore seems of fall under the heading of "you know it when you see it". If asked to quantify the things being measured, I am quite confident that I could have put some numbers on them, and with a larger sample size could have drawn some statistically significant conclusions.

For example, by inspection, the groups which seemed to be effectively addressing the team-working / time management criteria had a readily visible division of labour within the group. Some were writing up as the group went along , some were drawing the equipment used, whilst others were carrying out small scale experiments to prove principles. It seemed from this small sample size that such groups got a better result than those where everyone played with water for a couple of hours. However, even the very best groups did not seem to be putting together the applied maths they had learned with the hands-on, they were seemingly proceeding intuitively*.

Now, before I attempted to get a wider audience to believe my provisional conclusions, I would expect to have to justify my heuristics (is apparent diversity of tasks carried out by group members really a good marker of effective teamworking?), and bring some statistically significant numbers to the argument. However, as the ultimate aim of the exercise was to come up with a practical solution to a simulated problem, all observers seemed to agree that degree of workability of each group's solution was the most important variable. That this seemed to correlate to fluffier things like team-working and communication skills may have been an feature of the design of the exercise.

But were teaching outcomes being measured, or was this essentially a baseline measurement? These students were only eight weeks into the course, and had not directly been taught any of the things being measured, nor were most of these skills required as part of their pre-university study.

When I first crossed the boundary into the engineering space, in a module of my first, non-engineering degree called "Principles of Process Technology", we were taken into a large unfamiliar room full of large unfamiliar equipment, similar to that in which I spent some of yesterday. One of the lab supervisors yesterday called it a "Cathedral of Engineering", and these multi-storey rooms where one first encounters big kit do have that sort of impact.

A man who seemed quite different from the academics we had met up to that point told us that those of us who liked tinkering with our cars and bikes would find the module pretty straightforward, but that others (specifically the women and Asians present) would find it difficult. I was course rep. and of course I complained about the stereotyping, there was however a point obscured by his casual racism and sexism.

Some people do have an aptitude for Engineering, and I think that after such a short period of study, this may well be the majority of what was being measured by yesterdays' exercise. The exercise did not incidentally support the suggestion that sex or skin colour are reliable ways to spot these people, or the assessment exercise could have been a great deal shorter.

*The best design to my mind was a funnel connected by a hose to an inverted, cut down, 2l pop bottle. As water passed upwards through the inverted bottle, the contents were classified by means of their particle sizes, density and solubility in water in a single stage. The students saw this, but they didn't integrate the maths they knew, so they didn't attempt to calculate how much energy would be necessary to run their rig, or what might cause problems. (I'm doing this as much as anything because the exercise made me want to have a go!) They had a table for another part of the exercise which allowed them to determine how much head of water would be required to push a given volume of water through the hose, and they had recently studied the maths of buoyancy. So to fluidise the most difficult component of the mixture the students had to separate (sand which looked to be of about 16/30 grade), they would need about 400l/h of water upflow in a 100mm diameter pop bottle. Their 10mm bore hose should only have around 1m of headloss at this flow, so (adding a margin of safety) a few metres of static head should have been sufficient to effect the separation, as long as they did not restrict the flow with a blockage. This design as built should have been close to workable, if the mixture had been added gradually, and care taken that the heaviest component didn't block the inflow.

If it walks like a duck....Science, Social Science or Pseudoscience?

A few years back, I was diagnosed with cancer. If this ever happens to you (especially if it is essentially untreatable as mine was), be assured that all sorts of people will suggest that you abandon faith in rationality, and turn to "alternative medicine".

Of course, as "alternative medicine" is "medicine" which doesn't actually work, this is a really bad idea if you have a life-threatening illness. Evidence based medicine is still rejected by some doctors for similar reasons to teachers' seeming resistance to rational investigation of the efficacy of their profession, but they are a tiny minority now. EBM works.

It has struck me recently that in much of teaching, the alternative IS the mainstream, and that genuinely evidence-based practice is seemingly rejected by most teachers on similar grounds to the rejection of conventional medicine by quacks and their hangers-on.

There is even direct crossover of supposed authorities, in the case of the likes of Rudolph Steiner, founder of both Waldorf Schools and his own branch of alternative medicine, promoted by the company he helped found, Weleda.

So what do teaching have in common with "holistic"therapies? It can be summed up in one damning sentence-their research base is largely at best pseudoscience (follow the link for detailed explanations of what is meant by each assertion, let's not argue about what you think I mean)

Pseudoscience "research" is invariably sloppy.

Pseudoscience begins with a hypothesis—usually one which is appealing emotionally...and then looks only for items which appear to support it.

Pseudoscience is indifferent to criteria of valid evidence.

Pseudoscience relies heavily on subjective validation.

Pseudoscience depends on arbitrary conventions of human culture, rather than on unchanging regularities of nature.

Pseudoscience always avoids putting its claims to a meaningful test.

Pseudoscience often contradicts itself, even in its own terms.

Pseudoscience deliberately creates mystery where none exists

Pseudoscience does not progress.

Pseudoscience attempts to persuade with rhetoric, propaganda, and misrepresentation rather than valid evidence (which presumably does not exist).

Pseudoscience argues from ignorance, an elementary fallacy.

Pseudoscience argues from alleged exceptions, errors, anomalies, strange events, and suspect claims—rather than from well-established regularities of nature.

Pseudoscience appeals to false authority, to emotion, sentiment, or distrust of established fact.

Pseudoscientists invent their own vocabulary in which many terms lack precise or unambiguous definitions, and some have no definition at all.

Pseudoscience appeals to the truth-criteria of scientific methodology while simultaneously denying their validity.

In pedagogical research, the far-out"alternative" to mainstream research would be practice based on real scientific research. Petty's "Evidence Based Teaching" still relies upon the supposed "authorities" like Gardner, who produce no real evidence to support their assertions.

In my discussions with Jenni Case, she told me that the social sciences do in fact progress, but that this progress consisted of a proliferation of untested theories, which she described as a "horizontal progression". This is as opposed to the "vertical progression" of real science where new theories are based upon known facts.

Is simple proliferation really progress? How does it help to have one more virtually baseless opinion on an issue? Doesn't this increase confusion, rather than clarity? Does not the proliferation of (for example) seventy-plus learning theories only mask the fact that they are all essentially groundless speculation? (It am led to believe that the few which do seem to have some value are rejected by teachers as coming from business research)

There are no proven facts in teaching as far as I know. There has been no progress in teaching in the history of educational research. The average O-level, A-level and first degree student clearly knows less to anyone who encounters them than their 1980 equivalents.

Jenni Case claims in her paper that teaching is harder than designing an aircraft, and someone told me recently that their ITT lecturer told that that it was harder than performing a liver transplant. If teaching is harder than these things, why is it that you can get a postgraduate teaching qualification without having a degree in any subject, and that you do not even need this qualification to teach?

They wouldn't allow someone of the educational level of a PTLLS candidate hold the pencil or scalpel respectively of the Aeronautical Engineer or surgeon, but they can teach a class after a six-week course with no prior qualifications other than mickey-mouse O-level "equivalents". How is this different from the Reiki practitioner's six week course which gives many of them the confidence to say that they can treat cancer when Professors of Medicine cannot?

Witchhunt over, one witch found

I have updated my "Barrier to Learning" post for anyone interested in how that panned out. I'll not interrupt the flow of the blog to go back to this issue again.

Application of theory to real life planning

So I'm pretty far into my attempt to apply my working hypothesis to some actual teaching materials, which I will be actually delivering in a couple of weeks to an audience of seventy M.Sc. students. The working hypothesis was as follows:

A. Investigate Marzano's recommendations:

1. Teachers should identify knowledge and skills that are targets of instructions
2. Teachers should identify and use specific instructional techniques for specific instructional goals
3. Teachers should regularly use instructional techniques that apply to all types of instructional goals

I propose to investigate these by identifying the target knowledge and skills of the exercise, and deliberately applying specific instructional techniques to each of them. A reasonably full range of techniques shall be used, even if not identified as directly applicable. I will however limit the range of techniques used to those I have observed in use by lecturers at this level in this subject. No need to get too avant-garde. Evaluation of degree of success of techniques will be achieved by assessment of formative assessment exercises, and questionnaire.

B. Consider Hattie's recommendations where Marzano seem inapplicable

I have not identified a weakness in Marzano at this point

C. Use a mixture of types of material and techniques, biased towards materials and techniques suited to the material being taught.

So from a practical point of view, my first task is to identify what I attendees are supposed to know and to be able to do by the end of the session. I have been given a bit of help here by my client, who would like their students to be presented material on the applications of a particular sort of engineering process to a number of kinds of waste-water treatment. They would also like them to be able to do certain sorts of calculation.

So cut down from Marzano, we can understand that there are stated and implicit goals as follows:

Knowledge Goals

Information:

• understanding of key vocabulary terms understanding of important details
• understanding of organizing ideas

Mental Processes:

• ability to perform subject-specific algorithms
• ability to perform subject-specific tactics
• ability to perform subject-specific processes

Cognitive Goals

Storage and Retrieval:

• ability to store and retrieve knowledge

Basic Information Processing:

• ability to analyse the validity and reasonableness of new knowledge

Input/Output Processes:

• ability to comprehend information presented orally
• ability to comprehend information presented in written or symbolic terms
• ability to communicate information in oral form
• ability to communicate information in written or symbolic form

Knowledge Utilization:

• ability to make decisions
• ability to solve problems
• ability to investigate issues

Metacognitive Goals

• ability to monitor and control:
• accuracy and precision
• clarity
• impulsivity
• intensity of engagement
• focus

Self Goals

• understanding their beliefs about how the world works
• understanding their beliefs about purpose and what is important in life

This part of things is easy. The descriptive stuff can be delivered by means of traditional lecturing, with Socratic questioning to check that students are at least awake (the session is booked as four straight hours!) This lecture time should be be broken up by workshops to practice carrying out exercises in process selection, sizing and pricing calculations.

Lectured material can be spread between powerpoint slides, the non-identical accompanying handouts, and additional material spoken by me, but not written down on either slides or handouts. Handouts will have a notes column to allow attendees to add in this material. The slides and handouts will be made available to the students in advance, but attendance and attention will be required to get all that is being delivered, and some of it will hopefully be provided by the attendees themselves.

I think at least one coffee break should be added in to the programme, as the most engaging programme and lecturer in the world would have difficulty holding any audience for four hours on highly technical material. I have also asked to split the group down into ten groups around common tables for the workshop sections at least.

So how to make things interesting enough to carry such a long period off, as well as teaching something under Marzano's " Cognitive Goals" heading, now that my pole-dancing days are over?

I have a presentation and workshop covering most of the required material which I gave a few years back as part of a campaign to promote this particular process. This material is in several places wildly oversold, and the supporting arguments have blatantly dodgy assumptions.

Rational criticism can therefore be readily applied to see through the areas of overselling. I'll deliver the material more or less straight-faced, then invite the audience to tell me how I have twisted the facts to make a case. This can be used to lead into a discussion of the limits of applicability of heuristics, how the misapplication of rules of thumb can lead to erroneous assumptions, and the wisdom of conservatism in assumptions when you have little solid data.

As I am a lecturing as a visiting practitioner at present, I can be fairly straightforward about the difference of approach of the engineering practitioner and the academic in a way that I might have found challenging when I was a student, and see what that throws up. This will of course be a demonstration by example of the engineer's perspective.

How does all of this address Marzano?

Knowledge Goals

If the instructional goal is to enhance students’ understanding of vocabulary terms and phrases:

• Provide students with a brief description or informal definition of each word or phrase.

If the instructional goal is to enhance students’ understanding of details:

• Present the details in some form of story or elaborated description.
• Have students represent their understanding of the details in linguistic (e.g., notes, outlines) and nonlinguistic formats (e.g., pictures, semantic maps, charts, etc.).
• If the instructional goal is to enhance students’ understanding of organizing ideas (e.g., concepts, generalizations, principles):
• Demonstrate the organizing ideas to students in concrete terms.
• Have students apply the concept, generalization, or principle to new situations.

If the instructional goal is to enhance students’ ability to perform subject-specific algorithms:

• Present the various steps in the algorithm.
• Have students practice the algorithm paying particular attention to how it might be
• improved.
• If the instructional goal is to enhance students’ ability to perform subject-specific tactics or processes:
• Present students with general rules or heuristics as opposed to specific steps.
• Have students practice the tactic or process paying particular attention to how it might be
• improved.

Cognitive Goals

If the goal is to enhance students’ ability to store and retrieve knowledge:

• Provide students with strategies that use the representation of knowledge in nonlinguistic forms (e.g., mental images).

If the goal is to enhance students’ ability to identify similarities and differences, to analyse the reasonableness of new knowledge, to generate inferences about new knowledge, or to apply organizing ideas:

• Provide students with a set of heuristics, as opposed to steps regarding the processes involved.
• Have students practice the heuristics, paying particular attention to how they might be improved.

If the goal is to enhance students’ ability to make decisions, solve problems, or perform investigations:

• Provide students with heuristics for the overall processes of decision-making, problem-solving,and investigation, and have them practice the heuristics, paying particular attention to how they might be improved.
• Provide students with strategies for using what they know about the topics that are the focus of problems, decisions, and investigations.

Self Goals

If the goal is to enhance students’ understanding of and control of their beliefs about self attributes, self and others, the nature of the world, efficacy, or purpose:

• Have students verbalize their thinking relative to these areas.
• Have students make linkages between specific beliefs and specific behaviours in their lives.

So what has a lot of thinking based on theory and observation actually added to what I was doing before?

1. Use of different styles for delivery of different sorts of material and simply to change pace
2. Giving students material beforehand
3. Optimising room layout for type of delivery
4. Trying for "deeper" learning aims for the more able fraction of the class, whilst allowing the less able students to get the basics
5. Modifying session length from client specified to keep students more alert where needed
6. Perhaps a slightly different attitude to the process

I'll see what conclusions can be drawn from the observation and feedback. This seems like enough change to accommodate in a single session. After all, the way I was doing things before got a "Good" or better rating from students. We are tweaking here, not inventing from scratch.