Logging In

The following format, to flesh out teachers' ideas of the "big ideas" embedded within a particular topic is taken from Loughran, Berry and Mulhall's work on pedagogical content knowledge. The process is as follows. Firstly, the basic structure and the row columns are given. The column headings (ie the nominated "big ideas") and the details of each cell are prepared by teachers workshopping a topic; both the column headings and the details are worked on and modified as the teachers develop both. It is an iterative process.

The following explores the topic of "logging in", and was commenced on 17/9/2007 by Paul Chandler, Roland Gesthuizen and Tony Foster. It is significantly incomplete. Our brief meeting indicated that this approach was able to generate considerable valuable discussion and documentation about the "big ideas" and conceptual understanding. Your contribution to the grid is most welcomed.

As an indication of how the process worked, the idea of "model of the network you are logged into" was the second last "big idea" that we came up with, but as we talked further, it became clear that this was central to the other ideas; in fact possibly of primary importance, with the others following from it.

Model of the network you are logged on to
Knowledge of password
Authentication (trust)
What you intend the students to learn about this idea
. some idea of topology (that 'logging in' consists of at least 2 nodes)
. that network connections are not point-to-point
. therefore, some idea of routing and security
. easy to remember
. hard to guess
. the 'strength' of a password
. a general idea which applies to 'information about oneself'
. how widely is such data wittingly and unwittingly shared
. identity theft
. a property of the server
. with data provided by the user
. need to be careful about disconnects
. security keys
. a test of identity required by the server
. captcha
. not always used
. "100 point check"
. property of the server
. the server does not share passwords/ details with 3rd parties
. phishing
Why is it important for students to know this?

What else you might know about this idea (that you don't indent the students to know yet)

Difficulties/limitations connected with teaching this idea
. data is not really ever communicated as a unbroken bit stream; there is packetization, error recovery, latency, retries, etc
. notion that "hidden passwords" are hidden from the computer (linked to an anthopomorphic view of the computer)
. "can't trust friends", which is counter wisdom taught within a school community
. the extent to which 'confidential' is understood to be individual or collective will vary from one social/ethnic group to another

Knowledge about students' thinking that influences your teaching of this area

Other factors that influence your teaching of this area

Teaching procedures (and particular reasons for using these to engage with this idea)
. demonstrations of traceroute/ping
. ideas of latency

Specific ways of ascertaining students' understanding or confusion around this idea

Other "big ideas" which have been suggested are:
  • uniqueness of the identity
  • password security
  • unique network space is connected to the identity
  • identify the different spaces
  • login sequence
  • locking out
  • reading error messages
  • sometimes - none of the above are true