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Wednesday, September 24th, 2014
| Time |
Event |
| 12:00a |
Study: Online classes really do work It’s been two years since a New York Times article declared the “year of the MOOC” —short for “massive open online courses.” Now, for the first time, researchers have carried out a detailed study that shows that these classes really can teach at least as effectively as traditional classroom courses — and they found that this is true regardless of how much preparation and knowledge students start out with.
The findings have just been published in the International Review of Research in Open and Distance Learning, in a paper by David Pritchard, MIT’s Cecil and Ida Green Professor of Physics, along with three other researchers at MIT and one each from Harvard University and China’s Tsinghua University.
“It’s an issue that has been very controversial,” Pritchard says. “A number of well-known educators have said there isn’t going to be much learning in MOOCs, or if there is, it will be for people who are already well-educated.”
But after thorough before-and-after testing of students taking the MITx physics class 8.MReVx (Mechanics Review) online, and similar testing of those taking the same class in its traditional form, Pritchard and his team found quite the contrary: The study showed that in the MITx course, “the amount learned is somewhat greater than in the traditional lecture-based course,” Pritchard says.
Even the least-prepared learn
A second, more surprising finding, he says, is that those who were least prepared, as shown by their scores on pretests, “learn as well as everybody else.” That is, the amount of improvement seen “is no different for skillful people in the class” — including experienced physics teachers — “or students who were badly prepared. They all showed the same level of increase,” the study found.
Even if a student with a lower initial score still ends the online class with a test score that would represent a failing grade, that person would nevertheless have made substantial gains in understanding, Pritchard says. “This actually is a case where a rising tide lifts all boats,” he says.
The study’s basic methodology has been widely used to study the effectiveness of conventional on-campus classes, Pritchard says. At least 65 traditional MIT classes have been studied using the same system of pre- and post-testing of basic concepts, he says, but this is the first time anyone has applied such detailed, systematic testing to the effectiveness of an online class. Pritchard says the results show improvement among online students that is equal to or better than in any of the previously studied traditional classes.
In addition to the before-and-after testing, the study also analyzed in detail the homework and weekly test questions from each student, using an established technique called item-response theory, similar to the methodology used to ensure that results from standardized tests such as the SAT are consistent from one year to the next. The method uses a statistical analysis of each item in the test, Pritchard says, and includes a few of the same questions from other tests being compared, to ensure consistency.
Consistent results
Both of these methods of analyzing the impact of the online class give consistent results, Pritchard says: “All cohorts learn equally,” he says, whether compared on the basis of level of education, degree of preparation in math and physics, or other measures.
The one type of class in which students learned even more effectively than in either online or traditional classes, the study found, was an approach called “interactive engagement pedagogy,” where students interact frequently in small groups to grapple with concepts and questions. Such “constructive engagement” in the classroom is something education reformers have long pushed for, Pritchard says, and is already used in many MIT classes.
While a similar analysis could be done for any of the other roughly 1,000 classes currently available as MOOCs, he says, it requires an upfront commitment from course instructors, who must prepare and administer extra tests, and evaluate the scoring of those tests. “It’s a lot of work,” Pritchard says.
Pritchard sees the new study as just the start of a process of mining the data that can be gained from these online classes, where every detail of students’ interactions — how long they spend watching lectures, how often they pause or repeat sections, how much of the textbook they read and when, and so on — is recorded and could be used for research aimed at finding what systems work best. “We can study what students do in a way that would otherwise require everyone to wear a headcam all the time,” Pritchard says.
Fiona Hollands, a senior researcher at Teachers College of Columbia University who was not involved in this study, says, “In my opinion, this study represents the most rigorous attempt to date to measure learning in a MOOC. This study provides an excellent demonstration of how learning in a MOOC, or in other types of courses, can be rigorously assessed. Applied to a broader population of students and a variety of educational settings, such investigations would provide valuable information about the relative effectiveness of different forms of educational delivery.”
In addition to Pritchard, the study was carried out by MIT postdocs Kimberly Colvin and John Champaign and physics undergraduate Alwina Liu; Qian Zhou of Tsinghua University; and Colin Fredericks of Harvard. The research was supported by Google, the National Science Foundation, and MIT. | | 10:16a |
Community picnic to honor former ombudsperson Mary Rowe On Tuesday, Sept. 30, the MIT community is invited to attend a community picnic in celebration of the Institute’s culture of service and in recognition of the career of Mary Rowe, who retired as ombudsperson on Sept. 14 after 41 years of distinguished service to the Institute.
The picnic will run from noon to 2 p.m. on Killian Court. Its theme is “Our Community, Together in Service.”
MIT invites community members to bring items to the picnic for donation to local charitable organizations. Requests include canned or nonperishable foods for Cambridge’s Food for Free; school and art supplies for after-school programs at which MIT community members volunteer; and new or gently used books to be sold at the Community Giving at MIT book fair next month.
Community members who wish to donate food, supplies, or books in advance of the picnic may do so in Memorial Lobby (Building 10).
The picnic also honors the extraordinary career of Rowe, who arrived at MIT in 1973 as special assistant to the president and chancellor for women and work. In 1980, MIT President Paul Gray established the Ombuds Office and appointed Rowe and Clarence Williams as MIT’s first ombudspersons.
Among her many contributions to the MIT community, Rowe helped to create some of the Institute’s earliest mentoring and internal mediator programs. She has also helped to shape MIT’s policies around harassment and discrimination, conflict of interest, and other research-integrity issues.
From academic integrity to policy to dispute resolution, the Ombuds Office serves as an independent, confidential, neutral, and informal resource on a broad range of matters within MIT’s conflict-management system. Ombudspersons Toni Robinson and Judi Segall will be on hand at the picnic to provide additional information. | | 2:12p |
MIT completes advance refunding of bonds sold in 2008, 2009 Earlier this week, MIT priced an advance refunding of some $454 million of outstanding tax-exempt bonds that the Institute sold in 2008 and 2009. The transaction, which will be completed on Monday, allows MIT to “refinance” the debt from these earlier bond sales to take advantage of today’s low interest rates.
As part of the transaction, MIT issued $522 million in taxable debt, maturing in 2019, 2026, and 2038 and yielding 3.85 percent. However, the Institute’s overall debt load will only increase by about $69 million, because the 2008 and 2009 bonds will now come off its balance sheet.
The advance refunding affects two tax-exempt Series O and Series N bond issuances that MIT made in August 2008 and January 2009, respectively. Those issuances raised roughly $600 million that was used to finance construction of various capital projects, including the Koch Institute for Integrative Cancer Research, the MIT Media Lab’s Building E14, upgrades along Vassar Street, and other projects.
Of the initial $592 million par amount of debt issued, $50 million matured in July, and an additional $88 million will mature in 2016. The advance refunding affects the remaining $454 million, which was set to mature on four different dates between 2019 and 2038.
Under the terms of the 2008 and 2009 bond issuances, the Institute retained the right to call, or repay, those outstanding bonds early, in 2017 and 2018. The proceeds from this week’s transaction will go into a trust that will be used to pay off the remaining Series N and O bonds in 2017 and 2018, respectively.
Bond financing is a type of long-term borrowing frequently used to raise money for long-lived infrastructure assets. Investors purchase the bonds from the issuer, in this case MIT, which commits to making periodic interest payments and repaying the original principal over time or on a certain date. Bond investors typically include individuals, pension plans, mutual funds, and insurers. | | 11:59p |
Chemists recruit anthrax to deliver cancer drugs Bacillus anthracis bacteria have very efficient machinery for injecting toxic proteins into cells, leading to the potentially deadly infection known as anthrax. A team of MIT researchers has now hijacked that delivery system for a different purpose: administering cancer drugs.
“Anthrax toxin is a professional at delivering large enzymes into cells,” says Bradley Pentelute, the Pfizer-Laubauch Career Development Assistant Professor of Chemistry at MIT. “We wondered if we could render anthrax toxin nontoxic, and use it as a platform to deliver antibody drugs into cells.”
In a paper appearing in the journal ChemBioChem, Pentelute and colleagues showed that they could use this disarmed version of the anthrax toxin to deliver two proteins known as antibody mimics, which can kill cancer cells by disrupting specific proteins inside the cells. This is the first demonstration of effective delivery of antibody mimics into cells, which could allow researchers to develop new drugs for cancer and many other diseases, says Pentelute, the senior author of the paper.
Hitching a ride
Antibodies — natural proteins the body produces to bind to foreign invaders — are a rapidly growing area of pharmaceutical development. Inspired by natural protein interactions, scientists have designed new antibodies that can disrupt proteins such as the HER2 receptor, found on the surfaces of some cancer cells. The resulting drug, Herceptin, has been successfully used to treat breast tumors that overexpress the HER2 receptor.
Several antibody drugs have been developed to target other receptors found on cancer-cell surfaces. However, the potential usefulness of this approach has been limited by the fact that it is very difficult to get proteins inside cells. This means that many potential targets have been “undruggable,” Pentelute says.
“Crossing the cell membrane is really challenging,” he says. “One of the major bottlenecks in biotechnology is that there really doesn’t exist a universal technology to deliver antibodies into cells.”
For inspiration to solve this problem, Pentelute and his colleagues turned to nature. Scientists have been working for decades to understand how anthrax toxins get into cells; recently researchers have started exploring the possibility of mimicking this system to deliver small protein molecules as vaccines.
The anthrax toxin has three major components. One is a protein called protective antigen (PA), which binds to receptors called TEM8 and CMG2 that are found on most mammalian cells. Once PA attaches to the cell, it forms a docking site for two anthrax proteins called lethal factor (LF) and edema factor (EF). These proteins are pumped into the cell through a narrow pore and disrupt cellular processes, often resulting in the cell’s death.
However, this system can be made harmless by removing the sections of the LF and EF proteins that are responsible for their toxic activities, leaving behind the sections that allow the proteins to penetrate cells. The MIT team then replaced the toxic regions with antibody mimics, allowing these cargo proteins to catch a ride into cells through the PA channel.
‘A prominent advance’
The antibody mimics are based on protein scaffolds that are smaller than antibodies but still maintain structural diversity and can be designed to target different proteins inside a cell. In this study, the researchers successfully targeted several proteins, including Bcr-Abl, which causes chronic myeloid leukemia; cancer cells in which that protein was disrupted underwent programmed cell suicide. The researchers also successfully blocked hRaf-1, a protein that is overactive in many cancers.
“This work represents a prominent advance in the drug-delivery field,” says Jennifer Cochran, an associate professor of bioengineering at Stanford University. “Given the efficient protein delivery Pentelute and colleagues achieved with this technology compared to a traditional cell-penetrating peptide, studies to translate these findings to in vivo disease models will be highly anticipated.”
The MIT team is now testing this approach to treat tumors in mice and is also working on ways to deliver the antibodies to specific types of cells.
Lead authors of the paper are postdoc Xiaoli Liao and graduate student Amy Rabideau. The research was funded by the MIT Reed Fund, the Damon Runyon Cancer Research Foundation, and the National Science Foundation. |
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