Teddy Svoronos

Wireless Presenting Just Got a Lot Easier

Much has been said about Apple’s updates to Keynote, Pages, and Numbers last year, and much of that has been pretty negative. However, Apple has been rolling out updates to these apps over the past few months and, as of the latest update, has made a wonderful thing possible: it is now easy to wirelessly present and annotate a Keynote presentation with nothing more than an iPad, iPhone, and adapter.

Doing a wireless presentation on the go has been possible, but even the most well-done setups have required purchasing, bringing, and configuring additional devices (MacSparky’s setup, which I have used until now, requires a $99 Apple TV and a $99 Airport Express). Now, I only need three things which I carry around anyway: my iPad mini, my iPhone, and an adapter to hook an iOS device to a projector.

The Setup

The basic setup is to use your iPad as a remote that you carry around, which controls your iPhone that’s connected to the room projector[1]. Here are my steps for setting up a wireless Keynote presentation:

Connect my iPhone to the projector using the adapter
Pair the Keynote apps so that my iPad serves as a remote for my iPhone
Press Play on my iPad
Don’t be nervous and do a really good presentation

I’ll walk you through steps 1–3; you’re on your own for step 4.

Hardware: Connect your iPhone

This is easy. Both the VGA and HDMI adapters also have a power plug, so you can keep your iPhone charged while you project. As for which adapter to purchase, in my experience overhead projectors use VGA, while flatscreens use HDMI. That said, I work in academia, so you private sector folks with the fancy pants might only need HDMI to function.

Software: Pair the Keynote apps

The pairing process can feel a bit tedious, but only needs to be done the first time (your device is remembered for subsequent presentations). Better still, if you’re pairing iOS-to-iOS you don’t even need to be on the same network. Here are the steps:

Make sure Bluetooth is on for both devices
Open Keynote on both devices
On the iPad, tap the remote button on the main screen and tap Continue
On the iPhone, open a presentation
On the iPhone, tap on the wrench icon on the upper right of the screen and navigate to Presentation Tools > Allow Remote Control and turn Enable Remotes on
After taking a few seconds to pair via Bluetooth, your iPad should appear underneath Enable Remotes; tap Link
A passcode should show up on both devices; confirm that they’re the same number by tapping Confirm on your iPhone
Tap Done on your iPhone

Combined, here’s what it looks like on the iPhone:

and on the iPad:

Presenting

I said I couldn’t help you make an awesome presentation, but here’s a neat tip: as of this week’s Keynote updates, you can use your iPad to draw on your existing slides, and draw attention to parts of your slide using a laser pointer function. Here’s what it looks like in practice:

This means that you can walk around the room with iPad in hand, drawing and pointing to your heart’s content, all while projecting onto the room’s projector through your iPhone.

The best part? This is all I need for my new mobile presentation setup:

Enjoy, and please get in touch if you have ideas or suggestions.

In this post, I’m using the iPad as the remote and connecting the iPhone to the projector; this is because I prefer to use the iPad for annotations and reading notes. Feel free to switch the two if you prefer to have the iPhone in hand. ↩

MOOC Money

Caroline M. Hoxby recently published a NBER working paper on the role of MOOCs in the future business models of both “selective” and “non-selective” postsecondary institutions. The bulk of the paper would be interesting only to an economist, but the end is where things get interesting.

Hoxby argues that the current way that MOOCs are run (make your courses available publicly) could align with the business of non-selective institutions, in that students would pay to enroll in a course just like they would at a brick and mortar school. For “Highly Selective Postsecondary Education” (HSPE) Institutions (schools that rely heavily on alumni donations), though, Hoxby presents an alterative:

Viable online education for HSPE must deal with two problems: (i) the selectivity necessary for offering advanced education and (ii) the experiences that build the beliefs and adherence that sustain the venture capital-like financial model.

Consider a system in which HSPE institutions created online versions of their courses that could be traded with other institutions whose students had similarly high aptitude and preparation. The exporting institution could maintain the advanced nature of the course by limiting enrollment to those outside students who were best prepared, by disallowing outside students whose home institutions had previously sent students who underperformed, or by insisting that the outside students receive support (interactions and assessment) from an instructor at their home institution who is trusted by the exporting faculty member. Exporting institutions might offer such courses at a sustainable cost.18 A student’s home HSPE institution would continue to set his degree requirements, grant his degree, and be responsible for all other aspects of his PE experience.

I haven’t thought enough about this model to consider its implications, but this is one of the more novel pieces I’ve come across that speaks directly to how higher education business models can incorporate these new modes of teaching. If you’re aware of others, please do let me know!

Link: The Economics of Online Postsecondary Education: MOOCs, Nonselective Education, and Highly Selective Education

On Rigor

Lant Pritchett wrote a piece for the Building State Capacity blog about the notion of “rigorous evidence.” At the risk of putting words in his mouth, my sense is that his argument boils down to this: promoters of evidence-based policy overplay their hands by focusing exclusively on internal validity[1]. He says as much in his post:

Evidence would be “rigorous” about predicting the future impact of the adoption of a policy only if the conditions under which the policy was to be implemented were exactly the same in every relevant dimension as that under which the “rigorous” evidence was generated. But that can never be so because neither economics—nor any other social science—have theoretically sound and empirically validated invariance laws that specify what “exactly the same” conditions would be.

Pritchett raises an important point; our understanding of internal validity and our methods for assessing it are far more developed than that of external validity[2]. However, I can’t help but feel that Pritchett is overplaying his hand as well. We consider a study to be internally valid if our comparison groups are equivalent in expectation, not if they are exactly the same in every relevant dimension. This may seem like mincing words, but there’s a distinction between equivalence and plausibly arguing the absence of bias. The latter is the standard to which we hold studies when assessing internal validity, and we should do the same for external validity. Still, the point remains that our understanding of external validity is far removed from even this weaker definition.

Link: Rigorous Evidence Isn’t

Wikipedia’s entry on external validity vs. internal validity provides a nice overview of the tension for those unfamiliar with the concepts. ↩
A recent working paper by Hunt Alcott and Sendhil Mullainathan is an interesting foray into developing metrics for external validity. Unfortunately, these metrics seem to require a whole heap of data that is rarely available for a single intervention. ↩

EZ does it

While discussing research workflows with colleagues, I’ve been surprised to hear that many get the full text of a journal article by coming across an article, navigating to their school library website, searching for the journal under E-Resources, clicking on the journal link, digging down to the article of interest, and downloading it.

It doesn’t have to be this way (usually).

In most cases, links to journal pages through your library’s website are identical to their ordinary link + a suffix (called an EZproxy) that validates your school credentials to check if you have access. Thus, instead of:

http://jama.jamanetwork.com/journal.aspx

Your library’s link will look something like:

http://jama.jamanetwork.com.ezp-prod1.hul.harvard.edu/journal.aspx

Your browser can make this change through what’s called a ‘bookmarklet,’ a bookmark that, when clicked, does something with the existing URL in your browser. For my case, creating a bookmark with the following script as its content will redirect a journal’s site through my school library:

javascript:void(location.href='http://ezp-prod1.hul.harvard.edu/login?url='+location.href)

Alternatively, you can simply drag this EZproxy link into your browser bar.

Here’s a list of different schools’ EZproxy URLs. Edit the code above by replacing http://ezp-prod1.hul.harvard.edu/login?url= with your school’s URL.

In practice, this means that if you click this after trying to access a full PDF:

You get this:

Now, the caveat: this will not work for certain journals[1]. This may be because your school accesses that journal through some larger database, in which case you may have to go back to your library website, like an animal. But this works for me most of the time; hope you find it useful.

Note that this may simply be because your school doesn’t have access to that journal. Ugh, I know. ↩

Teaching Regression Discontinuity

A very enjoyable post on the regression discontinuity study design over at the must-read Development Impact blog. I was lucky enough to introduce this design to a room full of policy master’s students this semester, and I agree completely with all of Evans’ points. In addition to being a conceptually interesting design, RD is a great way to introduce students to the rationale behind quasi-experimental studies.