I’m trying to come up with an intuitive visualization of a mixed-effects model with a binary dependent variable and a binary independent variable as well as participant as random effect. What I’ve produced so far is this:

The problem here is that the graph with the lines sloping upwards suggests there are degrees between “yes/no”: the higher the independent variable the higher the dependent variable. The coding for both variables was, however, binary.

How can this graph be changed so that it reflects more adequately the binary nature of the variables? Or, what other visualization could be used for the model?

Data:

df <- structure(list(indvar = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 0L, 1L, 0L, 1L, 0L, 0L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 
1L, 1L, 1L, 1L, 1L, 0L, 0L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 0L, 
1L, 0L, 0L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 0L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 
0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 
1L, 1L, 1L, 0L, 1L, 0L, 0L, 0L, 0L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 
1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 1L, 0L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 
1L, 1L, 0L, 0L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 0L, 0L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 0L, 1L, 0L, 1L, 1L, 0L), depvar = structure(c(1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 
1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 
2L, 2L, 1L, 2L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 2L, 2L, 1L, 2L, 1L, 1L, 2L, 
2L, 2L, 1L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 
1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 
1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
1L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 
2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 2L, 1L, 1L, 
1L, 1L, 2L, 1L, 2L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 
2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 2L, 
1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 2L), levels = c("YES", 
"NO"), class = "factor"), raneff.pnp = c("GGGGGGGGGGGGGGGl", 
"IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "IIIIIIIIIIIIt", 
"IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "GGGGGGGGGGGGGGGl", "IIIIIIIIIIIIt", 
"IIIIIIIIIIIIt", "KKKKKKKKKKr", "IIIIIIIIIIIIt", "KKKKKKKKKKr", 
"IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "GGGGGGGGGGGGGGGl", 
"IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "KKKKKKKKKKr", "IIIIIIIIIIIIt", 
"IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "IIIIIIIIIIIIt", "IIIIIIIIIIIIt", 
"IIIIIIIIIIIIt", "DDDDDDDDDDDDe", "AAAAAAAAAAAAAn", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "CCCCCCCCCCx", "CCCCCCCCCCx", 
"DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "AAAAAAAAAAAAAn", "DDDDDDDDDDDDe", "CCCCCCCCCCx", 
"CCCCCCCCCCx", "CCCCCCCCCCx", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "AAAAAAAAAAAAAn", 
"DDDDDDDDDDDDe", "CCCCCCCCCCx", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "CCCCCCCCCCx", "DDDDDDDDDDDDe", 
"AAAAAAAAAAAAAn", "CCCCCCCCCCx", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "CCCCCCCCCCx", "CCCCCCCCCCx", 
"CCCCCCCCCCx", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"CCCCCCCCCCx", "DDDDDDDDDDDDe", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"CCCCCCCCCCx", "AAAAAAAAAAAAAn", "CCCCCCCCCCx", "DDDDDDDDDDDDe", 
"CCCCCCCCCCx", "DDDDDDDDDDDDe", "CCCCCCCCCCx", "DDDDDDDDDDDDe", 
"CCCCCCCCCCx", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLn", 
"CCCCCCCCCCx", "LLLLLLLLLLLLLn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "CCCCCCCCCCx", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "CCCCCCCCCCx", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "CCCCCCCCCCx", "AAAAAAAAAAAAAn", "LLLLLLLLLLLLLn", 
"LLLLLLLLLLLLLn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "LLLLLLLLLLLLLn", 
"AAAAAAAAAAAAAn", "CCCCCCCCCCx", "CCCCCCCCCCx", "CCCCCCCCCCx", 
"AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "CCCCCCCCCCx", 
"AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"CCCCCCCCCCx", "CCCCCCCCCCx", "LLLLLLLLLLLLLn", "AAAAAAAAAAAAAn", 
"CCCCCCCCCCx", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", "AAAAAAAAAAAAAn", 
"AAAAAAAAAAAAAn", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLo", "LLLLLLLLLLLLLo", 
"LLLLLLLLLLLLLn", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLo", "NNNNNNNNNNNr", 
"NNNNNNNNNNNr", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLn", "NNNNNNNNNNNr", 
"NNNNNNNNNNNr", "NNNNNNNNNNNr", "NNNNNNNNNNNr", "NNNNNNNNNNNr", 
"LLLLLLLLLLLLLo", "LLLLLLLLLLLLLo", "NNNNNNNNNNNr", "LLLLLLLLLLLLLo", 
"NNNNNNNNNNNr", "NNNNNNNNNNNr", "NNNNNNNNNNNr", "NNNNNNNNNNNr", 
"NNNNNNNNNNNr", "LLLLLLLLLLLLLn", "LLLLLLLLLLLLLn", "NNNNNNNNNNNr", 
"LLLLLLLLLLLLLo", "LLLLLLLLLLLLLo", "LLLLLLLLLLLLLo", "LLLLLLLLLLLLLn", 
"LLLLLLLLLLLLLo", "NNNNNNNNNNNr", "NNNNNNNNNNNr", "LLLLLLLLLLLLLn", 
"LLLLLLLLLLLLLn", "NNNNNNNNNNNr", "LLLLLLLLLLLLLn", "NNNNNNNNNNNr", 
"NNNNNNNNNNNr", "LLLLLLLLLLLLLo", "LLLLLLLLLLLLLo", "CCCCCCCCCCx", 
"LLLLLLLLLLLLLo", "DDDDDDDDDDDDe", "CCCCCCCCCCx", "LLLLLLLLLLLLLo", 
"LLLLLLLLLLLLLo", "LLLLLLLLLLLLLo", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "CCCCCCCCCCx", "DDDDDDDDDDDDe", "CCCCCCCCCCx", 
"CCCCCCCCCCx", "CCCCCCCCCCx", "CCCCCCCCCCx", "DDDDDDDDDDDDe", 
"CCCCCCCCCCx", "CCCCCCCCCCx", "DDDDDDDDDDDDe", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "DDDDDDDDDDDDe", "LLLLLLLLLLLLLo", "DDDDDDDDDDDDe", 
"DDDDDDDDDDDDe", "CCCCCCCCCCx", "CCCCCCCCCCx", "AAAAAAAAAAo", 
"AAAAAAAAAAo", "AAAAAAAAAAo", "AAAAAAAAAAo", "AAAAAAAAAAo", "AAAAAAAAAAo", 
"CCCCCCCCCCx", "CCCCCCCCCCCCCCx", "AAAAAAAAAAo", "AAAAAAAAAAo", 
"AAAAAAAAAAo", "AAAAAAAAAAo", "AAAAAAAAAAo", "AAAAAAAAAAo", "CCCCCCCCCCCCCCx", 
"AAAAAAAAAAo", "CCCCCCCCCCCCCCx", "SSSSSSSSSSd", "SSSSSSSSSSd", 
"GGGGGGGGGGGGGi", "SSSSSSSSSSd", "SSSSSSSSSSd", "AAAAAAAAAAo", 
"SSSSSSSSSSd", "SSSSSSSSSSd", "AAAAAAAAAAo", "SSSSSSSSSSd", "AAAAAAAAAAo", 
"SSSSSSSSSSd", "SSSSSSSSSSd", "SSSSSSSSSSd", "AAAAAAAAAAo", "SSSSSSSSSSd", 
"GGGGGGGGGGGGGi", "GGGGGGGGGGGGGi", "GGGGGGGGGGGGGi", "GGGGGGGGGGGGGi", 
"GGGGGGGGGGGGGi", "GGGGGGGGGGGGGi", "SSSSSSSSSSd", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"JJJJJJJJJJJJy", "JJJJJJJJJJJJy", "JJJJJJJJJJJJy", "JJJJJJJJJJJJJJJJJJd", 
"JJJJJJJJJJJJJJJJJJd", "JJJJJJJJJJJJJJJJJJd", "JJJJJJJJJJJJy", 
"JJJJJJJJJJJJJJJJJJd", "JJJJJJJJJJJJy", "JJJJJJJJJJJJy", "LLLLLLLLLLn", 
"CCCCCCCCCCCCd", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", 
"CCCCCCCCCCCCd", "OOOOOOOOOOOOm", "OOOOOOOOOOOOm", "LLLLLLLLLLn", 
"CCCCCCCCCCCCd", "OOOOOOOOOOOOm", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", 
"LLLLLLLLLLn", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", 
"LLLLLLLLLLn", "LLLLLLLLLLn", "LLLLLLLLLLn", "OOOOOOOOOOOOm", 
"CCCCCCCCCCCCd", "LLLLLLLLLLn", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", 
"OOOOOOOOOOOOm", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", 
"CCCCCCCCCCCCd", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", "CCCCCCCCCCCCd", 
"CCCCCCCCCCCCd", "LLLLLLLLLLn", "LLLLLLLLLLn", "LLLLLLLLLLn", 
"LLLLLLLLLLn", "OOOOOOOOOOOOm", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", "LLLLLLLLLLLLLLLLLLLl", 
"AAAAAAAAAAo", "XXXX", "XXXX", "XXXX", "XXXX", "XXXX")), row.names = c(NA, 
337L), class = "data.frame")