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US CED Rarity Assessment


I was unable to obtain any original pressing records from either RCA or CBS about the actual quantities of each CED title pressed, so another means had to be devised to generate the rarity rating for each title. This involved using both quantitative and qualitative factors to arrive at the individual rating for each title.

Quantitative Analysis

I only collected CED's in thrift stores for the first couple years, but beginning in 1989, I started running want ads in newspapers and in publications like Big Reel, Discoveries, Goldmine, Nuts & Volts, and the LaserDisc Newsletter to track down additional titles. I also posted want ads to Usenet and modem-based services like AOL, AppleLink, eWorld, Prodigy, GEnie, and CompuServe. This generated quite a lot of responses, as back in these days before the explosive growth of the Internet there were a lot of people with a stack of CED's who wanted to get rid of them, but didn't know where. I saved all the letters and emails sent and later realized that these each represent a random small sample of CED's that combined could be used to come up with a frequency of occurrence for each CED title. The taking of a number of small samples and using them to come up with a figure for an entire population is an accepted scientific method used extensively in biology, agriculture, and polls. I began this analysis in July 1997 and little-by-little completed it in April 1998. Since a lot of the data came from hand-written letters, there was no easy means to automate the compilation process.

During this same period, I ran an on-line Rarity Survey at CED Magic to compile data on titles that have identical names. Most of the letters and emails used in the analysis above didn't specify the version for titles released twice under the same name, so the Rarity Survey was used to determine a percentile distribution for each identically named title. The Rarity Survey is still available to those who haven't yet completed it. I'll periodically recompile the data as new surveys continue to trickle in. Much thanks to these participants in the Rarity Survey, as well as to those who chose not to be identified.

Qualitative Analysis

Although the quantitative analysis contained about 80,000 samples, I felt that other factors need to be considered to determine the rating for those titles that turned up only a few times in the analysis. If I had adhered to a strictly quantitative analysis, a title that appeared three times would have been Very Rare, but that same title would be Rare if it had appeared four times. Now if that title was a movie that had been pressed in 1984, and had remained available to purchase for a couple more years, I may have given it a Rare rating. On the other hand, a Vestron movie released in late 1985 may have been assigned a Very Rare rating even if it had appeared four times, as the final Vestron releases were pressed in very small quantities. Here's a list of the qualitative factors I considered, in order of importance:

Explanation of the Rarity Ratings

It became apparent during the quantitative analysis that most CED's exist at about the same frequency of occurrence, while the rest were more common or rarer (sometimes considerably rarer). In other words, a graph with frequency of occurrence on the X-axis and number of titles on the Y-axis would result in the Bell-shaped curve everyone is familiar with. I chose the center of this bell curve as the Uncommon rating and looked for a natural break above and below this to determine the Common and Rare ratings. The Very Rare rating was reserved for titles that appeared only three or fewer times in the 80,000 sample, and Extremely Rare was used for titles that otherwise would have been Very Rare, but had some other factor making them even more non-existent. For example, The Story of O was canceled by RCA after a partial press run. Some of these discs made it out of RCA in the hands of employees, but the title was never offered for retail sale.

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