Parsed with column specification:
cols(
  .default = col_double(),
  rank = col_character(),
  ethnicity = col_character(),
  gender = col_character(),
  language = col_character(),
  cls_level = col_character(),
  cls_profs = col_character(),
  cls_credits = col_character(),
  pic_outfit = col_character(),
  pic_color = col_character()
)
See spec(...) for full column specifications.
Rows: 463
Columns: 6
$ score      <dbl> 4.7, 4.1, 3.9, 4.8, 4.6, 4.3, 2.8, 4.1, 3.4, 4.5, 3.8, 4.5, 4.6, 3.9, 3.9, 4.3, 4.5, 4.8, 4.6, 4.6, 4.9, 4.…
$ age        <dbl> 36, 36, 36, 36, 59, 59, 59, 51, 51, 40, 40, 40, 40, 40, 40, 40, 40, 31, 31, 31, 31, 31, 31, 62, 62, 62, 62,…
$ gender     <chr> "female", "female", "female", "female", "male", "male", "male", "male", "male", "female", "female", "female…
$ bty_avg    <dbl> 5.000, 5.000, 5.000, 5.000, 3.000, 3.000, 3.000, 3.333, 3.333, 3.167, 3.167, 3.167, 3.167, 3.167, 3.167, 3.…
$ pic_outfit <chr> "not formal", "not formal", "not formal", "not formal", "not formal", "not formal", "not formal", "not form…
$ pic_color  <chr> "color", "color", "color", "color", "color", "color", "color", "color", "color", "color", "color", "color",…

1 - Os dados

Os dados que usaremos estão detalhados nessa página do OpenIntro.

De início, verifiquemos os números da pesquisa:

profs %>%
  summarise('Quantidade total de professores' = n())
profs %>% 
  group_by(gender) %>%
  summarise('Quantidade de professores' = n())
profs

2 - Relações dos dados com a nota

Vimos que há outras variáveis fora a nota, mas o que precisamos saber de fato é se essas outras variáveis influenciam na nota, vejamos:

profs %>% 
    ggplot(aes(x = age, y = score)) + 
    geom_count()

profs %>% 
    ggplot(aes(x = bty_avg, y = score)) + 
    geom_count()

profs %>% 
    ggplot(aes(x = pic_outfit, y = score)) + 
    geom_count()

profs %>% 
    ggplot(aes(x = pic_color, y = score)) + 
    geom_count()

Primeiro, vejamos estatísticas de relação entre o sexo e a nota de cada professor:

profs %>%
  summarise(media_nota = mean(score))
profs %>%
  group_by(gender) %>%
  ggplot(aes(y = score, x = "", colour = gender)) +
  geom_quasirandom() +
  geom_abline(slope = 0, intercept = 4.17473, color = "red", size = .3) +
  facet_wrap(~ gender) +
  labs(title = "Genero x Nota", x = "Generos", y = "Notas",
       subtitle = "Linha vermelha = média geral")

profs %>%
  ggplot(aes(y = score, x = "")) +
  geom_quasirandom() +
  facet_wrap(~ pic_outfit)

3 - Todos os dados

Vejamos o quanto cada característica influencia na nota da didática do professor:

glance(model_profs)

4 - Conclusão

Com essas tabelas, obseva-se que a equação da reta que corresponde ao valor de score é:
- \(score = -0.0071*age + 0.2233*gender + 0.0473*btyAvg - 0.2123*picColor - 0.0151*picOutfit + 4.3701\)

Tendo em vista que valores que são tratados como strings se transformam da seguinte forma na equação:

  • gender:
    • male = 1
    • female = 0
  • pic_color:
    • color = 1
    • black/white = 0
  • pic_outfit:
    • not_formal = 1
    • formal = 0

O \(R^2\) é 0.08775, ou seja, \((R^2 * 100)\)% = 8.7%, representa pouco menos que 9% da avaliação de didática que os alunos fizeram de cada professor.

Ou seja, conclui-se que:
- O gênero masculino obteve melhores notas na votação.
- Fotos coloridas na pesquisa são piores votadas que fotos pretas e brancas, pois a estimativa do coeficiente é negativo.
- Professores com roupas formais são votados com notas mais baixas que professores com roupas não formais.
- A idade tem uma influência negativa na nota, ou seja, quanto mais velho, menor a nota, mas tem uma influencia pouco significativa. - A beleza tem uma influência positiva na nota da didática dos professores.

Nota-se que características externas influenciam na didática dos professores, porém, esses número apenas representam 8.7% da avaliação dos alunos, ou seja, não representa muito bem todos os números.

Nota-se também que há outras variáveis relacionadas com as que são observadas nesses dados, ou seja, váriaveis influenciando variáveis, o que deixa mais claro o resultado e a influencia de fatores externos na avaliação da didática dos professores.

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w6F2ZWlzIHJlbGFjaW9uYWRhcyBjb20gYXMgcXVlIHPDo28gb2JzZXJ2YWRhcyBuZXNzZXMgZGFkb3MsIG91IHNlamEsIHbDoXJpYXZlaXMgaW5mbHVlbmNpYW5kbyB2YXJpw6F2ZWlzLCBvIHF1ZSBkZWl4YSBtYWlzIGNsYXJvIG8gcmVzdWx0YWRvIGUgYSBpbmZsdWVuY2lhIGRlIGZhdG9yZXMgZXh0ZXJub3MgbmEgYXZhbGlhw6fDo28gZGEgZGlkw6F0aWNhIGRvcyBwcm9mZXNzb3Jlcy4gCgoKCg==