Practical advice

Real survey data is messy

Distance sampling in the Real World

  • We've talked a lot about models
  • We've also talked about assumptions
  • Our example is relatively well-behaved
  • What can we do about all the nasty real world stuff?

Some days...

2 fire emoji, a computer emoji, 2 fire emoji


  • Here we want to cover common questions
  • Not definitive answers
  • Some guidance on where to look for answers

What should my sample size be?

What do we mean by "sample size"?

  • Number of animal (groups) recorded
    • detection function
  • Number of segments
    • spatial model
  • Number of segments with observations
    • spatial model


How would we know when we have enough samples?

  • We don't
  • Heavily context-dependent
  • Go back to assumptions

"How many data?"