Good, Bad and Wrong: Videos about Confidence Intervals

Which comes first – problem or solution?
8 April 2013
Is statistical enquiry a cycle?
22 April 2013

Videos are useful teaching and learning resources

There is much talk about “flipped classrooms” and the wonders of Khan Academy, YouTube abounds with videos about everything…really! Even television news reports show YouTube clips. Teachers and instructors use videos in their teaching, and get their students to watch them at home, ready to build on in class time. A well put-together video can provide a different way of looking at a problem that helps a student to learn. Videos are endlessly patient and can be paused and watched at the students’ pace. (See my earlier post on multimedia for a fuller discourse on good multimedia.) The problem is: How is a teacher to know what is good and what is not? This seems to be especially difficult in an area like statistics.
I decided this week to see what was on offer and summarise for you all. To narrow it down I chose the topic of Confidence intervals. This topic is pretty universal to statistics courses, and is conceptually tricky. I wanted to see if there was a quick way of working out if a video is any good or not, without having to watch them. I was prepared to suffer so that my readers would not have to.

Videos about confidence intervals are mostly awful

And suffer I did. Not to beat around the bush – many of the videos I watched were awful. There is no other word for it. Not only were they slow, boring, mathematically based, unscripted and unedited, but many of them were just plain wrong. Back in 2008 I went looking for a video about confidence intervals for my students, and realised I had to make my own. It is still true. I do not doubt that the videos are well intentioned. Many of them may have been made (as mine were originally) for a specific class (or family member), and thus were not intended for a larger audience. Maybe those ones should come with disclaimers. “I’m not sure I really know what I am talking about – view at your own risk.”
I put “Confidence Intervals” into the YouTube search engine and examined nine of the top offerings. Mostly I went for the videos with the most views, as this would appear to be a way of filtering out poor material. (wrong again, as you will see) I also included two of my own videos.
Most these videos should not be seen by a wider audience. No – that’s not right – most of them should not be seen – by anyone. The impression they give of statistics is of a bumbling professor talking about formulas and looking up tables. Nothing in them gives a single hint about how interesting, applied and relevant the subject of statistics is. Maybe there needs to be a wikipedia approach to supposedly educational videos to provide quality control.There is just one video other than my own two that I approve of – by Keith Bower. (Biased, I know – feel free to respond.)
A possible way if you wish to find useful videos, might be to get the students to find a video they think is good, then you check that it is correct. Trying to find a good video about statistics is not a good use of your time – unless of course, you just go straight to the Statistics Learning Centre channel or Keith Bower.  🙂
If any of you gentle readers have a video you think is worth a second look, please put the link in the comments.

Brief reviews of ten videos on Confidence Intervals in no especial order except that I left the three good ones until last

I started with the videos that appeared at the top. They have paid to be first in the list, so I thought they might be good. As it turns out they are very similar to each other and from the same stable, it seems. I found them lacklustre, though not totally harmful.
1. Statistics – Confidence Intervals
Channel: EducatorVids2                Videos on the channel: 1192
17268 views  Loaded 24 Oct 2011 (32 views per day)    Duration 3:25
This video and the next one are part of some sort of course. This video seemed to start in the middle of a lecture “Now let’s go on to some examples”. The layout was utilitarian, with a talking head, and a screen showing the  working. The video, like most of them, was not scripted. The content was based on a Mathematical example with no context. I don’t really know what she was talking about. But at least it was short.

2. Statistics: Confidence Intervals (Difference in Means)
Channel                    Videos on the channel: 1914
7381 views, loaded 5 Nov 2009  (6 views per day) Duration 3:46
Very similar format to EducatorVids2. The bulk of the content was around a medical example with  7 subjects. Again it was not scripted. The  computation was tedious so that I had to fast forward.

And here is the one you have all been waiting for: Khan Academy. I should know better than to suggest that the mighty Khan is less than perfect (my previous post about KA  continues to provoke defensive vitriol.) But here goes:
3. Confidence Interval 1
Khan Academy                                  Videos on the channel: 3492
167, 213 views, loaded 28 Oct 2010 (186 views per day) Duration 14:03
246 likes 20 dislikes.
Like all Khan Academy videos (as far as I know) the format is very simple with a black screen with printed example. Again the video is not scripted, and consists of a lot of repetition as Khan doesn’t like empty air while he is writing.It is actually a lead into confidence intervals, doing a theoretical exercise involving the sampling distribution. Thus it talks about probabilities.  It would have been better to entitle it, preparation for confidence intervals, as it doesn’t actually teach about confidence intervals, and includes probability. Khan included steps to using tables to find a t value. This video was really not nice.  And it took 14 minutes! That is 14 minutes I will never have again. It is also a long time to find out that it doesn’t actually teach about confidence intervals. This video is one of the worst of the ten I viewed, and has far more views than it ought.

4. Statistics is easy: Confidence Interval
aghasemi4u                           Videos on the channel: 4 about statistics
a remarkable 296,456 views, loaded 23 March 2007, (136 per day)  Duration 5:00
186 likes and 83 dislikes
This video was simple and reasonably well put together, with nice diagrams, but only three slides in its five minutes.  The narration is unscripted and uses probability to describe the confidence interval (wrong!). There was a focus on the mathematical formula.

5. . Confidence Intervals
Madonna USI                          Videos on the channel: 22
18,403 views        Uploaded 9 Nov 2009 (15 per day) Duration 9:42
102 likes, 2 dislikes
A brief description of what confidence intervals are as well as a couple examples.Live person working on a whiteboard. Refers to a textbook. Very slow. Definition wrong – Says that we are 95% confident that the value that we found is within the range. I’m hoping this is just a slip of the tongue, but it should have been editted out.

6. How to calculate Confidence Intervals and Margin of Error
Statistics is fun                  Videos on the channel: 80
25,750 views.   Uploaded 12 July 2011 (40 per day) Duration: 6:44
145 likes, 3 dislikes
Summarised before and after, which can be tedious. Mathematically based. Slick graphics, but glacially slow in parts. Gives an example with no context. This is not statistics! Tedious. To be fair, there are lots of positive comments, and as the title says “how to calculate confidence intervals” there is no requirement to explain what they are when you get them. The channel is all about “how to calculate” and nothing about context, so I think it is a bit of a misnomer to call it “Statistics is fun”.

7. Confidence Intervals Part1 YouTube
Larry Shrewsbury Videos on the channel: 15
82,006 views. Uploaded on 12 Jul 2009 (128  per day) Duration 7:42
136 likes 53 dislikes
Part of an enterprise “Taking the Sadistics out of learning Statistics”
I found the voice irritating as it seems patronising. However some people find my accent distracting, (wot eksent?) so I can’t really be too hard on that. Very formula based, looking at the mathematics rather than the interpretation. The best part was an interesting animation – very nice way of looking at traditional confidence intervals that I hadn’t seen before.

Here are the three good videos:

8. The history, use and certain limitations of confidence intervals in statistics.
Keith Bower   Videos on the channel: 49
32,883 views. Uploaded 5 Jan 2009 (21 views per day) Duration:3:25
66 likes, 5 dislikes
Keith’s presentation isn’t visually exciting, but he is correct and clear and that goes a long way. His is just a talking head – but he is an interesting presenter and very fluent. His video has branching, such that you can click to go to another video if needed. I’ve found all his videos sound and sensible. (I got “p is low, null must go” from one of his videos.)

9. Confidence Intervals in Excel
UCMSCI              Videos on the channel
17797 views  Loaded 25 Dec 2008 (11 per day)
26 likes 0 dislikes
This was one of my earlier videos. It is scripted with visuals to help in comprehension. It takes the classical approach to confidence intervals and puts emphasis on the idea of level of confidence. Addresses the aspects that affect the width of confidence intervals. Discusses the formula for confidence intervals, and shows how to use Excel to calculate them. (I don’t think I really loaded it on Christmas day! Maybe some strange dateline thing)
10. Understanding Confidence Intervals: Statistics Help
Statistics Learning Centre   Videos on the channel: 19
550 views    Uploaded 26 March 2013  (31 per day)  6 likes 0 dislikes Duration: 4:02
This video will disappoint the mathematicians, as there are no formulas. But students love it. The point of the video is to explain what a confidence interval is, and what things affect the size of the interval. It makes use of diagrams and examples to help students understand the concepts. It is tightly scripted and edited with no wasted time. People can always pause if they need to, but it is difficult to speed up a slow presentation.

Epilogue (Obituary?)

And there you have it, folks – there is no easy way to work out which videos are going to be useful for your students without watching them all. Sorry. And if you expect me to go through this again with another topic, you clearly didn’t get the subtext.


  1. Richard says:

    did you also look in itunesU?

  2. Joan Hendrikz says:

    I liked your videos, Nicola, especially the one about apples, and the earlier one explained well what a CI means especially in terms of the 100 samples. However, at one stage I thought your example was about ‘ticks’ until I realised that your Kiwi accent had distorted the word ‘texts’ to my unaccostomed Aussie ears!

    • Dr Nic says:

      Thanks. I once lost a set of disks at a conference in Melbourne and the poor organiser was looking for a set of desks! Slightly differing sizes.

  3. No video but have a graph for teaching regression to the mean that is a simple way to get the concept across.

  4. Priscilla says:

    Now I feel bad for all the unscripted, classroom teaching videos I have put on YouTube to help my students! The Wikipedia idea is good, sort the off the cuff, informal videos from the well planned professional ones? Thing is my students find them helpful, and they are not intended for a wider audience, but making them public helps locating them.

    • Dr Nic says:

      That’s a good point – the videos I have seen of yours are fine and fit the purpose for which they are intended. I think it is great that you do them, and I’m sure your class do appreciate it. Maybe it would be good to put in the intro that they are aimed at a certain class. The problem is that there isn’t a good sorting method, and we are at the mercy of the YouTube and Google search engines. And Khan Academy who are paid money and produce poor unscripted videos.

  5. Well done for persevering with these videos! We need more reviews like this. Maybe I should steel myself and do one too. I always warn students about YouTube, and I’m sure they understand it’s not 100% trustworthy, but later I hear that they have been confused by looking at it anyway. It’s nice to have a written review I can refer to so it doesn’t just sound like my old-fashioned opinion!

    • Dr Nic says:

      Thanks. The problem is that there IS the odd good material on YouTube (I like to think mine is!) but it is difficult to know whether something is reliable or not. Maybe Wikipedia could start having video links as well. Either on the relevant page, or a separate page called Videos about statistics. I’ve found Wikipedia to be really useful and either sound, or with markers to indicate that it might not be. I love and give money to Wikipedia.

  6. […] video or similar to watch. This is not as easy as it may sound. As you can see from my critique of videos about confidence intervals, there is a lot of dross from which to extract the gold. And Khan Academy is no […]

  7. […] Just over a year ago I wrote a balanced review of some of the Khan Academy videos about statistics. I know that statistics is difficult to explain – in fact one of the hardest subjects to teach. You can read my review here. I’ve also reviewed a selection of videos about confidence intervals, one of which was from Khan Academy. You can read the review here. […]

  8. Mark says:

    Thanks for this post. It’s a shame you didn’t achieve your goal of finding a way to identify the best videos without watching them. However you have inspired me. I’m a six sigma black belt and I always dread teaching some of these more complex statistical concepts to our green belts. The materials we are provided to teach with are dry and uninspiring. Believe it or not, it never occurred to me before reading this to find better teaching aids on YouTube. I’ll definitely be giving it a try next time…even if I do have to watch them myself first!

  9. […] A traditional approach to teaching confidence intervals is to start with the concept of a sampling distribution, followed by calculating the confidence interval of a mean using the Z distribution. Then the t distribution is introduced. Many of the questions involve calculation by formula. Very little time is spent on what a confidence interval is and why we need them. This is the order used in many textbooks. The Khan Academy video that I reviewed in a previous post does just this. […]

  10. […] most of my videos do just that – my “Understanding Confidence Intervals” is possibly the only video on confidence intervals that does not include a calculation or […]

  11. […] setting out to make videos about confidence intervals, I critiqued the existing offerings in this post. At the time the videos were all about how to find a confidence interval, and not what it does. I […]

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