Internally valid
The 5 different session increases the strength
For example the use of emotional test to determine if Albert was a calm and even-tempered baby with no prior fear reactions
Increases the internal validity and means they have a legitimate measure of the effects on conditioning fear responses
Replicable study
Use of controlled observation + standardised procedures (procedures filmed)
They can check for consistencies in results on effect of conditioning fear as they can replicate it from footage
Increases the external reliability