Instead, the teachers and coaches I met were quiet, even reserved. They were mostly older; many had been teaching thirty or forty years. They possessed the same sort of gaze: steady, deep, unblinking. They listened far more than they talked. They seemed allergic to giving pep talks or inspiring speeches; they spent most of their time offering small, targeted, highly specific adjustments. They had an extraordinary sensitivity to the person they were teaching, customizing each message to each student’s personality.
On John Wooden: Gallimore and Tharp recorded and coded 2,326 discrete acts of teaching. Of them, a mere 6.9 percent were compliments. Only 6.6 percent were expressions of displeasure. But 75 percent were pure information: what to do, how to do it, when to intensify an activity.
What if an investment returned 5%, 20%, and 50% over three years?
Year 1: $100 * .05 = $105
Year 2: $105 * .20 = $126
Year 3: $126 * .50 = $189
What was the annual return? Can you just average the percentages?
Let’s try it. The average of 5%, 20%, and 50% is 25%
Did you average 25% a year?
Year 1: $100 * .25 = $125
Year 2: $125 * .25 = $156.25
Year 3: $156.25 * .25 = $195.31
No, 25% for 3 years gets you a different amount!
You calculate the average annual return via the geometric mean (not the arithmetic mean)
Your annual return was actually 23.6%
Year 1: $100 * .236 = $123.6
Year 2: $123.6 * .236 = $152.77
Year 3: $152.77 * .236 = $188.82
- The results revealed that while the two types of note-takers performed equally well on questions that involved recalling facts, laptop note-takers performed significantly worse on the conceptual questions.
- The benefit of having more content is canceled out by “mindless transcription.”
- The amount of verbatim overlap was associated with worse performance on conceptual items.
What You Miss When You Take Notes on Your Laptop
- Mueller and Oppenheimer predicted that the decrease in retention appeared to be due to “verbatim transcription.”
- And again, though the laptop note takers recorded a larger amount of notes, the longhand note takers performed better on conceptual, and this time factual, questions.
A Learning Secret: Don’t Take Notes with a Laptop
- Students who used longhand remembered more and had a deeper understanding of the material
Investing heavily in school computers and classroom technology does not improve pupils’ performance, according to a global study from the OECD.
I noticed a for sale ad for a 1996 Mustang, and was struck by the $3500 price… ’94-‘04 Mustangs seem like a great bang for the buck: They are cheap, plentiful, have lots of parts available, and there’s lots of online DIY support. Perfect for a student or hobbyist on a budget.
I opened up 35 ads and noticed 19 were manual. I realized I was staring at a confidence interval problem!
If you have the only cell phone in the world, it’s pretty useless, since you can’t call anyone. If there are 2 cell phones, there is one possible connection. If there are 3 cell phones, you can make a total of 3 connections. 4 cell phones can have a total of 6 connections. 5 cell phones? 10 connections. 6 phones means 15 connections.
The more devices there are, the most connections you can make. The more connections there are, the more useful the whole network becomes. This is also called Metcalf’s Law.
Let’s look at the sequence of numbers generated above.
1, 3, 6, 10, 15, …
Can you see the pattern? The number of connections can be represented by where n is the number of nodes in the network. Notice that this is very similar to . So, the number of total possible connections is proportional to the square of the number of nodes in the network.
Is this bad science? Since this is a retrospective study, there is non-random assignment for the treatment and control groups. That introduces selection bias. Projects that are more likely to implement a (long-winded) “waterfall” life-cycle approach are probably larger scale projects to begin with. Correlation is not causation. So, maybe it’s not the lifecycle approach that is the problem, but the confounding/lurking variable of project scale that is the problem. The study should control for the size of the project to make a valid conclusion about success rate of the development approach used. ie: Building a large insurance processing system will use a lifecycle approach, while building a fitness app will not. Apples to oranges, since one is much easier to be implement than the other.