

snails(MASS)                                 R Documentation

_S_n_a_i_l _M_o_r_t_a_l_i_t_y _D_a_t_a

_D_e_s_c_r_i_p_t_i_o_n_:

     Groups of 20 snails were held for periods of 1, 2, 3 or
     4 weeks in carefully controlled conditions of tempera-
     ture and relative humidity.  There were two species of
     snail, A and B, and the experiment was designed as a 4
     by 3 by 4 by 2 completely randomized design.  At the
     end of the exposure time the snails were tested to see
     if they had survived; the process itself is fatal for
     the animals.  The object of the exercise was to model
     the probability of survival in terms of the stimulus
     variables, and in particular to test for differences
     between species.

     The data are unusual in that in most cases fatalities
     during the experiment were fairly small.

_A_r_g_u_m_e_n_t_s_:

 Species: Snail species A (1) or B (2)

Exposure: Exposure in weeks

 Rel.Hum: Relative humidity (4 levels)

    Temp: Temperature, in degrees Celsius (3 levels)

  Deaths: Number of deaths

       N: Number of snails exposed

_F_o_r_m_a_t_:

     The data frame contains the following components:

_S_o_u_r_c_e_:

     Zoology Department, The University of Adelaide.

