Socio-Scientific Issues in STEM Education: Mathematics

The Case of Sally Clark (or statistic used wrongly)

In November 1999, Sally Clark, a respected lawyer, is charged with the murder of her children. Clark was suspected of murder after her two sons (*1996, *1997) died of sudden infant death syndrome within a short time after their birth. In the trial, the renowned pediatrician Professor Sir Roy Meadow was called in as an expert witness. He based his testimony on a statistical study which stated that the probability of a crib death in a family of the Clarks' social status was about 1 in 8543. From this, Meadow concludes that the probability of two such deaths occurring in the same family was equal to the square of that number:

1 in 73 million

Based on this statistical analysis, Sally Clark is found guilty of murdering her two children.

  • What is the mathematical argument behind Meadows argumentation.
  • Are the accusations justified? Do you agree with Dr. Meadow? Discuss this from a scientific and  from an ethical viewpoint.







SSIs in this Example

Characteristics of SSIs

How to use SSIs in STEM Ed

1. Argued by authory?

The gravity of the expert wittnesses testemony was undermined by his title of nobility. 
Criticisms of the ruling initially received little attention.

2. Conviction by probability?

The verdict based on a mainly statistical argumentation neglecting thepersonal circumstances and not, as it may look like, a trial based on circumstantial evidence.

3 .Did sociological, psychological, political or media factors influence the case?

  • Crime against children usually cause great stir. 
  • The media coverage of sally clark portrayed her as a murderer.


• SSIs have a basis in science and require people to engage in dialogue, discussion, and debate.

• They are mainly controversial in nature. 

• They require forming opinions and making decisions including scientific, moral, ethical or social reasoning issues.

Dealing with SSI’s

• Dealing with these issues requires evaluating incomplete information because of conflicting or incomplete scientific evidence and incomplete reporting

• Often these issues involve a cost-benefit analysis in which risk interacts with ethical reasoning.

The goal is to understand how different opinions evolve and strengthen.

  1. Read the text carefully!
  2. How do you position in this context!
  3. Put yourself in the role of an expert. How would you argue…
    1. … if you oppose the case?
    2. … if you do not oppose the case?
  4. Do your own (internet) research.
    1. Find list of (seemingly) scientific based arguments favoring respectively opposing the arguments in this case
    2. Elaborate on the connection between the case and scientific facts. 
  5. What other aspects influence the perception of this case?

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