A Comparison Of The Ergonomics Of Alphabetical and Numerical Sequences Of Different Lengths And the Influence Of Presentation On Data Entry And Recall Tasks

Researcher Scarlett Oporto

Supervisors A/Prof Laurence Hartley

Date: 17th November, 2010

Organisations use a variety of codes to identify people, objects and locations; however the most widely used code systems are alphabetic and numeric in nature. Airline companies use alphabetical codes to identify other airlines, local and international airports; and some airlines have begun using alphabetical codes to identify their customers. Similarly, the United States military use alphabetical codes to denote both health and career statuses of officers. In contrast, other organisations such as banks and universities utilise numerical codes to identify accounts and students or staff respectively. Since there is no universally accepted code system, questions have been raised as to whether certain codes are more memorable and less confusable than others, and whether the ways in which these codes are presented also play a role in the memorability and subsequent entry of sequences into data entry devices.

As such, the aim of the current experiment was to determine whether there is a certain type of sequence and presentation that is more memorable and less confusable than others across different string lengths. Thirty-eight participants were presented with alphabetical and numerical sequences of various lengths (four-, six-, eight-, ten- and twelve-characters long) and in either grouped or ungrouped formats, under both recall and data entry conditions. The study found that there was no particular code type and/or presentation which could facilitate recall and data entry. The manner in which sequences were presented did not influence memorability or data entry in terms of accuracy. Although numerical information was found to be more accessible than alphabetical sequences, alphabetical codes were recalled more accurately (however this was not the case for all string lengths). In contrast, there were no differences in accuracy between different sequence types in data entry tasks. Hence it was suggested that memorability plays a greater role in the ergonomics of code types when compared to influence of data entry on QWERTY keyboards. Despite these results, it remains unclear how ungrouped strings can facilitate accessibility of information from memory. The techniques used to retrieve alphabetical sequences from memory also remain unclear. In addition to this, from the results obtained, not much can be said about the ergonomics of alphanumeric strings and how they compare to alphabetical and numerical sequences. As such, further studies should be carried out in these areas to help organisations gain a better understanding of the ergonomics of different code types and the influence of presentation.