You know that it’s important to keep your eLearning files small.The bigger your files, in most cases the slower they will be to open, save, andedit. In addition, unnecessarily large files stand a bigger chance of gettingcorrupted, especially when you save the file to a network drive.
On top of that, when you publish your lesson you may findthat the resulting set of files is larger than needed, making your lessondifficult to deliver across anything but the fastest internet connections. Sohow do you keep your eLearning files light? Let’s explore the ways.
Your content
The buzzword for the last few years has been microlearning. It has its supporters anddetractors. Like any other idea, it makes sense in some areas and not inothers. I’m convinced that the main reason that this movement started is thatlearners complained that lessons were too long, boring, and pointless.
Focus your content on the main point. Don’t crowd it with alot of extra material. If you feel strongly that those sections should beincluded, make them optional or accessible through links.
Just get to the point!
Your design approach
You certainly don’t want to create learning that is a lot oftext with little else. However, the solution for many designers is to retainall that text and spice it up with images that may be tangentially supportive ofthe lesson topics. So you end up with lots of pictures of people sitting arounda table, executives shaking hands, or a construction worker leaning on ashovel. Do these really help learning happen? I argue they don’t.
What if learning was more like the Choose Your Own Adventurebooks? Those books contain few, if any, images, but they’re engaging andinteresting because after reading a few paragraphs, you have to decide the nextstep to take, hence jump to page x ory. The resulting story could differtremendously depending on the path you took.
Isn’t that the point of eLearning? Letting learners makedecisions in a safe environment and see the consequences of their actions? I’mnot suggesting your eLearning should be all text, but take great care choosing images,audio, video, and other elements that weigh down your learning. They should behelping learners understand better, not distracting them.
Media, of course
There’s no question that the biggest culprit in increasinglesson file sizes is the use of images, audio, and video. However, that’s notan excuse to create just plain vanilla eLearning with text bullets! There are plenty of ways to ensure that your media files won’t weigh down your learning files.
Images
When you import images into your lessons, it’s OK if youneed to adjust their sizes a little. However, if you import an image that has awidth of 2,000 pixels and a height of 1,500 pixels, and the maximum size youneed the image to be in your lesson is 500 x 375 pixels, it’s an excellent ideato first resize the image to the smaller resolution in an image editor beforeyou import it in your authoring tool (Figure 1). Do this with all the images that you import and you’reguaranteed to have a smaller file size.
Figure 1: Resize images before importing. This photo does not needhigh resolution.
As you’re aware, there are many formats for images,including BMP, JPG, PNG, GIF, and others. The same image stored in one formatmay have a much larger file size than in other. This is because a file formatmay be:
- RAW:Not compressed at all, so the largest file size. Most digital cameras let you savephotos to RAW format for the best possible quality.
- LOSSLESS:Compressed in such a way that you could convert it back to RAW.
- LOSSY:Compressed in various ways to reduce file and transmission size. Depending onhow compressed it is and the method of compression, the image should still lookvery good to the human eye.
The above all refer to the most common types of images weuse and see and are typically called raster,pixel-based, or bitmap. Almostall photographs and many drawings fall into this category.
Important: Check if your authoring tool converts all imagesyou import to specific formats, such as JPG or PNG, regardless of whether theimported images were BMP or another format. If so, you may find that it’sbetter to convert your images first to those formats before importing them intoyour lesson for maximum file size savings.
Scalable vector graphics
If your authoring tool supports importing vector graphics(SVG), strongly consider using them instead of another format. SVG aretypically images drawn in a tool like Adobe Illustrator, Inkscape, Method Draw,or Adobe XD (Figure 2). The file contains XML-tagged information that allowsthe browser to reconstruct the image instantly and faithfully at whatever sizeyou like. There is no blurring or pixilation, and the file sizes are verysmall. Again, these are not for photographs, only for drawn images. In aproject I’m working on, almost every image the client provided was in SVGformat. The resulting lesson file size is much smaller than it would have beenif I had used raster images.
Figure 2: A logo saved as a scalable vector graphic (SVG).
By the way, scalable vector graphics also come in different formatsfor architectural drawings, CAD-CAM, and many other fields. The standard forHTML5 is SVG, so you should convert to that format first.
Audio
You know that friend of yours that swears that music onrecord albums is superior to the music on your MP3 player? Well, it’s true,because that audio on vinyl is in analogformat, whereas all the music stored on computers and devices is digital, which means it must beconverted and, in most cases, compressed. We talk to each other in analog, andour microphones pick up our voices in analog as well, but that microphone isattached to a computer, which converts that analog signal into digital. Conversionshrinks the dynamic range between the quietest and the loudest parts of theaudio. It makes the quieter signals louder and lowers the louder parts as well.You may find that this lowers the music’s quality.
We rarely use music in eLearning, though. Most audio in eLearning is narration. The dynamic range for human voices,especially for male voices, is much tighter than for music.
As with images, audio compression can be lossless or lossy. Most music formats are lossy, with MP3 being the standardfor web delivery.
You can likely convert those huge audio narration files intomuch smaller formats without any noticeable degradation in quality. If you lookat the properties of a sound file on your computer, you will see that it isstored using a certain bit rate, forinstance, 256kbps. Three main factors determine the bit rate:
- Samplerate: Can be as high as 192,000 hertz or as little as 8,000 hertz. CDs use44,100 hertz, but I have found that for typical narration, 22,050 hertz givesthe same results.
- Bitdepth: Usually set at 8, 16, 24, or 32. The higher the number, the moredetail in your audio. For narration, you’ll find that a bit depth of 8 is fine,and you won’t get any extra detail with higher numbers.
- Channels:Usually this is set to 1 (mono) or 2 (stereo). For most narration, stereois unnecessary, and you can cut an audio file size in half by saving it asmono.
While there are many audio file formats, the standard forweb delivery is MP3 and you may find that your authoring tool will convert allaudio you’ve imported to that format.
Video
Just as for audio, there are several factors that determinethe file size of your videos. The most important are:
- Framesize: The width and height of your video. Definitely do not import videosthat are larger in width and height than you need. Resize your video to thelargest size needed before you import it into your lesson. The difference infile size can be huge.
- Framerate: The number of frames per second. Video is nothing more than a seriesof photos. The number of photos you display each second is the frame rate.While 29.97 fps is standard for television and other professional media, youmay find that a frame rate of 24, 12, or even 8 fps will work for your videos,depending on how much movement and action are in the videos. For instance, atalking head will require a much slower frame rate than showing a car racingalong a highway.
The audio your video files contain also should be addressedusing the suggestions in the audio section above.
Online video
If your video is already resident or if you can place it ona fast video server, either your own or a site like YouTube, you can avoidweighing down your eLearning files by simply linking to the video through a webobject in your authoring tool. Almost all authoring tools now support webobjects; even PowerPoint allows you to include them. If it’s possible to do so,you may find it very advantageous.
Your thoughts
I have found that using the methods I’ve described helplearners engage and enjoy eLearning a lot more than wading through a lot ofunnecessary material or seeing and hearing media that doesn’t really add value.When media does add value, having it delivered fast, without delay, also helpsto keep learners engaged.
What do you do to ensure your eLearning is light and tight?Write your comments below.
