Data entry in 2014: the vivid learnings of card punching

Pondering data quality checks? Considering elaborated, automated (and expensive) schemes? Let me suggest card punching.

Punch cards? Depending on your age, you will either take me for a fool (meaning you know what a punch card is…), or simply ask “what is this?”. Let’s start with a short presentation. Basically, a punch card looks  like this:


This type of card has been used to record instructions for processing, starting in the early eighteenth century, especially in the highly standardized industries, such as textile; on a more romantic standpoint, it also is the basic material for barrel organs… It has then been used rather for data storage as of the middle of the twentieth century, and it has been one of the key drivers of the IBM success in the early ages of Data Processing.

But punch cards are not used any more, and this, since the late eighties… So, in this area of highly digitalized working environment, what are the learnings of such “analog” tools?

Actually, the cards themselves are not the important thing, it is how they have been used, and what we may re-use nowadays. The punching system required at least three major conditions to work, each of them reinforcing the quality of the whole process; these steps were: standardization, precise instructions and double data entry. Let me explain each in a few words.

  • Standardization has been a prerequisite to implementing punch cards, as they had to be readable from one machine to another… IBM made their worldwide success on their 80-character column standard (which was also the width of a terminal screen…). Standardization still is an asset for Data Entry, especially to provide an homogeneous frame to any operator (or operating system) performing data entry onto your systems. A well-design data entry system endorsed by the whole company is already a very good step towards data quality.
  • Precise instructions are needed to ensure your processing flows smoothly, as one cannot afford to have two people understand a process differently, even slightly. When given multiple choices, the operator has to know what to do in ALL the potential options, so that no human factor may be implied in quality. This is the step where machines are better, provided these machines do not have to do too much rendering. For instance, reading an image and entering the data as numeric or alphanumeric code still is quite difficult nowadays, even though the best engineers are working on it (see this Google project about cracking House Number Id’s in Google Street View).
  • Double data entry is the key quality control when talking about punching cards. The puncher/checker duet (in French, we name this “perfo/vérif”) has been the most efficient way to ensure correct data entry in the past, as these small holes in the card were not self-explanatory, and mis-punching was easy. So double data entry has been the best way to guarantee satisfactory levels of data quality, at least in a standard environment, with regular levels of investment (some automated systems, especially using the latest neural network techniques, may be more efficient, but definitely are more costly to implement…).

Let me elaborate more about Double Data Entry (DDE); DDE still is a very efficient way of improving quality. The chart below sums it up clearly:

DDE Error Rate

The percentage of recorded errors falls down dramatically when two people run the same process in parallel, and then compare their results. Similar rates are reached when running the process in a sequence, e.g. when someone checks the outputs of another (both methods are valid, the latter requesting a supervision, e.g. a different human relationship between the two data entry operators…).

I understand that these statistics have been collected ages ago, in times when the machine was good enough to be a repository, but not an operator itself, but I strongly believe that the simplest methods are still to be taken into account, at least where quality (customer satisfaction) is preferred over quantity (lowest costs). And even if one is rather keen on processing quantitatively, one cannot keep their customers on the long term without a decent (i.e. high) level of quality…

So, on top of more recent data processing ways, there is a lot to learn also from the card punching working methods. And this may certainly widely apply to your business… Should you have quality issues, you certainly would want to look into implementing such sound and simple working methods on top of your existing QC. And I would be glad to help you assess them.

Finally, there is still a way to use punch cards, even though in a humorous mode… Maybe some schizophrenic geek will love this way of googling: Punch Card Google… Still, the request processing looked a bit fast compared to my recollection 😉

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