Sampling bias, or rather, experience/observer bias, is another aspect of this.<p>In 2015 I explored the question of how much user activity there was on Google+. My initial approach was to look at the <i>public posting</i> activity (which is most visible), but a criticism was that there might be some massive amount of <i>private</i> sharing going on (apparently by accounts which had never posted publicly). I did a follow-up analysis looking at the listed <i>followers</i> ("friends" in FB parlance) of publicly inactive and publicly active profiles.<p><i>The most overwhelming impression was how many profiles -- publicly active or otherwise, had a shockingly small number of followers.</i><p>The <i>median</i> for publicly inactive profiles: 2. For publicly active ones: 5.<p>The 95%ile: 33.5 for inactives, 69 for actives.<p>This jarred with the experiences of those I was hearing criticism from <i>simply because they were, virtually by definition, extreme outliers.</i><p><a href="https://ello.co/dredmorbius/post/naya9wqdemiovuvwvoyquq" rel="nofollow">https://ello.co/dredmorbius/post/naya9wqdemiovuvwvoyquq</a><p>Public vs. non-publicly posting profiles summary data<p>Publicly Inactive<p>Followers:<p>n: 88, sum: 561, min: 1, max: 53, mean: 6.375000, median: 2, sd: 10.953730<p>%-ile: 5: 1, 10: 1, 15: 1, 20: 1, 25: 1, 30: 1, 35: 1, 40: 2, 45: 2, 55: 2, 60: 3, 65: 4, 70: 4.5, 75: 6.5, 80: 7, 85: 10, 90: 19.5, 95: 33.5<p>Views:<p>n: 88, sum: 638656, min: 265, max: 119442, mean: 7257.454545, median: 1012.5, sd: 17720.702361<p>%-ile: 5: 298.5, 10: 335, 15: 368.5, 20: 408.5, 25: 477.5, 30: 503, 35: 570.5, 40: 689, 45: 912, 55: 1211, 60: 1340, 65: 2027.5, 70: 2824.5, 75: 5245, 80: 7893.5, 85: 12777.5, 90: 21663, 95: 48144.5<p>Publicly Active<p>Followers:<p>n: 1890, sum: 125539, min: 1, max: 67855, mean: 66.422751, median: 5, sd: 1579.404405<p>%-ile: 5: 1, 10: 1, 15: 1, 20: 1, 25: 2, 30: 2, 35: 2, 40: 3, 45: 4, 55: 6, 60: 7, 65: 8, 70: 10, 75: 13, 80: 18, 85: 24, 90: 34, 95: 69<p>Views:<p>n: 1890, sum: 66647773, min: 252, max: 21088213, mean: 35263.371958, median: 3419.5, sd: 522757.797486<p>%-ile: 5: 576.5, 10: 855.5, 15: 1076, 20: 1311, 25: 1566.5, 30: 1847.5, 35: 2153.5, 40: 2518, 45: 2947, 55: 4045, 60: 4890, 65: 5982.5, 70: 7645, 75: 10157, 80: 13468, 85: 18576, 90: 27814.5, 95: 54290<p>More: <a href="https://plus.google.com/u/0/104092656004159577193/posts/RhnKkfTNPKR" rel="nofollow">https://plus.google.com/u/0/104092656004159577193/posts/RhnK...</a>