1) There are only two ways of child faeces disposal: safe and unsafe. Faeces are disposed safely when put in an improved sanitation facility (pit latrine with slab, ventilated improved pit latrine, flush/ pour toilet connected to a sewer system or a septic tank, composting toilet).
2) Especially when the respondent says that s/he disposes of the children's faeces into (any type of) improved sanitation facility, it is important that the data collector goes and sees whether 1) the sanitation facility is really an improved model; and 2) whether it has signs of being used.
3) Ensure that all data collectors have a good understanding of what "an improved sanitation facility" means and are able to recognize it.
4) It is recommended that this question is asked before the data collectors starts asking about other sanitation-related topics. Otherwise the respondent will likely reply what s/he thinks the "correct answer" is.
5) Ask this question only to households with children younger than 3 years. Often, the younger the children are, the more likely it is that the caregivers do not dispose of her/his faeces safely.