NASA gets dramatic. But the drama is oh so appropriate when you see what they have to do to land a rover on Mars. There are so many steps to the landing — heat shields, atmospheric friction, parachute, rockets — that it’ll be amazing if it works, and the video is a wonderful “strike the imagination” introduction to the physics of forces.
Month: June 2012
Positive to Negative Feedback: Three to One (at least)
Three positives for every one negative is the minimum ratio required for people to flourish, according to the work of Marcial Losada (and others).
To flourish means to live within an optimal range of human functioning, one that connotes goodness, generativity, growth, and resilience.
— Fredrickson and Losada: Positive Affect and the Complex Dynamics of Human Flourishing (ᔥ PubMed), in American Psychologist (2005).
Why do we need more positives than negatives? Because we’re impacted more by negatives than positives, so we need more positives to offset. Note that people tend toward happiness on average.
Why are positive feelings good? Positivity increases:
- the scope of your attention. Making it possible to see the bigger picture (see Hirsh and Anderson, 2007 (pdf));
- intuition;
- creativity;
- physical healing;
- the immune system (at least in conjunction with mindfulness meditation: see Davidson et al, 2003);
- resilience to adversity;
- happiness;
- psychological growth;
- cortisol (positivity reduces cortisol levels — cortisol is a stress hormone; see Steptoe et al., 2004);
- resistance to physical pain;
- how long you’ll live.
- how much you learn.
In terms of education:
… initially positive attitudes—like interest and curiosity—produce more accurate subsequent knowledge than do initially negative attitudes—like boredom and cynicism. Positivity, by prompting approach and exploration, creates experiential learning opportunities that confirm or correct initial expectations. By contrast, because negativity promotes avoidance, opportunities to correct false impressions are passed by …. positive affect—by broadening exploratory behavior in the moment—over time builds more accurate cognitive maps of what is good and bad in the environment. This greater knowledge becomes a lasting personal resource.
— — Fredrickson and Losada: Positive Affect and the Complex Dynamics of Human Flourishing (ᔥ PubMed), in American Psychologist (2005).
So, once again, research shows how important it is to have a positive (happy) learning environment, and to be able to “spark the imagination” at the beginning of a lesson.
Cumulatively, there is the Losada Zone, a range from 3:1 to 11:1 of positive to negative feelings that are indicative of complex (good) interaction in groups, which separates people who flourish from those who languish.
Epigenetics: How our Environment Affects what our Genes Do.
The middle-school introduction to genetics tends to start with Mendel‘s pea experiments and end with Punnet Squares. The focus is on dominant and recessive genes and what’s expressed given various combinations.
However, the way genes behave are not quite that simple. Tim Spector’s new book, Identically Different, goes into the ways that people’s behavior and environment — the things they eat; the chemicals that surround them — affect the way their genes behave. Even identical twins can be profoundly different depending on things that happen in the womb.
Perhaps the most intriguingly argument is that the behavior of grandparents can affect their grandchildren. In the post World War II period in Britain food was scarce, and some people tended to episodes of starvation alternating with binge eating. Spector links this to an increase in the obesity of their grandkids.
The idea that your behavior can affect the expression of your kids’ genes is more akin to Lamark’s view of evolution than Darwin’s.
DarwinTunes: Watching Music Evolve
Take randomly generated sound waves (using sine curves for example), mix them together to get beats, and then let people decide which ones sound best. Let the best ones mate — add in small mutations — and wait a few thousand generations for the sound patterns to evolve into music.
That’s what DarwinTunes does, and they let you participate in the artificial selection process (artificial as opposed to natural selection).
The details are included in their article: Evolution of music by public choice by MacCallum et al. (2012).
Slow Motion Popcorn
The Slow Mo Guys do popcorn:
Meaningful Progress: The Ultimate Motivator
Motivation is key to learning. Amabile and Kramer (2011) explain that strong motivation has been an essential driver in scientific discovery and the business world as well. They assert that:
Of all the things that can boost emotions, motivation, and perceptions during a workday, the single most important is making progress in meaningful work . And the more frequently people experience that sense of progress, the more likely they are to be creatively productive in the long run [my italics].— Amabile and Kramer, 2011: The Power of Small Wins in Harvard Business Review.
So for education, we need to design work so that students can be challenged (which makes it meaningful), yet be able to make good progress. It’s a delicate balance to get each student into their “flow zone“, where the work is neither too hard, nor too easy.
The Best Color Scale? Not Rainbow
Even though rainbow color maps look pretty, Borland and Taylor (2007; pdf) argue that they’re rarely the best choice for showing data.
The rainbow color map confuses viewers through its lack of perceptual ordering, obscures data through its uncontrolled luminance variation, and actively misleads interpretation through the introduction of non-data-dependent gradients.
–Borland and Taylor (2007): Rainbow Color Map (Still) Considered Harmful in IEEE Computer Graphics and Applications.
They recommend the much more boring (but visually useful) greyscale and bi-colored schemes, for things like temperature maps and so on where the data is continuous.
Starting Algebra too Early?
There’s been a push for students to take algebra earlier and earlier, yet there are some serious pedagogic arguments that early algebra might not be a great idea for many, if not most, students. A fascinating paper by Clotfelter et al., (2012) (pdf) showed pretty clearly that for a large number of students, taking algebra earlier actually resulted in worse performance in not just algebra, but the follow-up classes as well (geometry and pre-calculus for example), compared to students who waited to take the subject. Indeed the Charlotte-Mecklenburg School District (the district studied in the article) actually reversed their policy of having students take algebra in 8th grade.
Students affected by the acceleration initiative scored significantly lower on end-of-course tests in Algebra I, and were either no more likely or significantly less likely to pass standard follow-up courses, Geometry and Algebra II
— Clotfelter et al., (2012): The Aftermath of Accelerating Algebra: Evidence from a District Policy Initiative (pdf) via NY Fed.
The argument for early algebra comes from the correlation between early algebra and better performance on standardized tests, and more advanced math classes in high school. But the authors here indicate that forcing students to take algebra early does not result in the same outcomes.
The argument against early algebra is based on the research that shows formal thinking develops during adolescence, and the belief that to do well in algebra requires the abstract thinking skills that are seated in the maturing prefrontal cortex. Until students are ready for the abstract thinking required (which happens at different times for each student), they will struggle with algebra.
Algebra provides an essential foundation for further mathematics, which is why it is my strong preference that students progress by demonstrating mastery of the topics at their own pace rather than struggling through the class.