0:00:03i'm so first an undergraduate student in developmental psychology at boston college with their core
0:00:08test
0:00:09this is our video abstract for the people coming out in developmental science called one
0:00:13two three and a b c's development stress and logarithmic two linear responding reflect fluency
0:00:19with sequence that is
0:00:21this paper looks at performance on the number line placement task originally developed by see
0:00:26lower and upper and this task look something like this
0:00:31there's going to be a line between two and points
0:00:34but the small and point on the left and a larger weight on the right
0:00:37children are not also be given a target number and asked to place the number
0:00:41where belongs on the one
0:00:44for example children might be given the number five and asked where belongs
0:00:48but the correct answer being in the middle
0:00:53many researchers the use this task to show that it's predictive ability in particular performance
0:00:58on this task is correlated with performance on a other estimation task
0:01:03and on magnitude comparison task
0:01:06it is also be used to develop pretty successful educational dimensions
0:01:10so it seems to be something really important about this time this predictive about competency
0:01:15was last clear as wide so predictive
0:01:18and different colleague suggest that is projected because it provides direct information about children's underlying
0:01:24representation of number
0:01:27and using this assumption they provided a data suggest that children's underlying representation of number
0:01:32go through a qualitative change over development
0:01:37charger base their values in a logarithmic distribution over the line
0:01:41well older children tend of these values in a more linear distribution over the line
0:01:47so you calling seventy in this behavior of data to suggest a developmental trend in
0:01:52the underlying representation a number
0:01:56so over time chosen one shows a representation from primarily logarithmic well to a primarily
0:02:01linear one
0:02:03however in this paper we provide data a against the assumption that this talk provides
0:02:08direct information about the underlying representation of number
0:02:12instead we suggest that a performance on this task is dependent on familiarity with the
0:02:18magnitude of a voice and fluency with ordered sequence which is not necessarily a numerical
0:02:24or magnitude based in nature
0:02:27to test our first hypothesis we provided a lot with the non-standard number line placement
0:02:32tasks
0:02:33here not a time points around points that do not and in zero which are
0:02:37typically that points used in these tasks like one hundred or one thousand
0:02:41so i don't received a task and point of one thousand six hundred and thirty
0:02:45nine and two thousand eight hundred and ninety seven
0:02:48as opposed to control tasks or most standard and points but a similar magnitude so
0:02:53two thousand three thousand and another with standard endpoints
0:02:56both the similar range
0:03:00i results show that i don't a logarithmic on the non-standard endpoint task disliking linear
0:03:06on the similar magnitude and similar range tasks with standard error points
0:03:11meaning and place the and in zero
0:03:13therefore i suggest that we do slow rhythm in performance but this is not indicative
0:03:19of their underlying representation of number
0:03:22since there you're on the same range on the same magnitude of target values but
0:03:28with when we provide standard and so on at least one of the and white
0:03:32and zero
0:03:34we can apply an analogous arguments of a single data single children and then when
0:03:39there are longer it on the first one thousand it may not be necessarily that
0:03:43their underlying representation of the numbers from zero to one thousand or logarithmic a but
0:03:48instead of their less familiar with a weight of one thousand
0:03:53a results of the second part of our hypothesis using about placement tasks with children
0:03:58so that all of that as an ordered sequence but there's no underlying or inherent
0:04:04magnitude in the letters
0:04:08children are given the same setup but with and points of eight and c and
0:04:12then asked to place the target letter where belongs on the line
0:04:17in this task we see that younger children at six to seven respond algorithmically by
0:04:23older children extend to alignment respond are linearly and the children in the middle are
0:04:27showing a mix of it here
0:04:29so we're showing the exact same developmental trendy and the alphabet policemen task
0:04:34which is an ordered sequence with no one here and magnitude of the scene and
0:04:37the number of placement tasks
0:04:39suggesting that the pattern of responding
0:04:41lively does not reflect the underlying representation of magnitude
0:04:46solo the number line placement task seems to be indicative of something important which is
0:04:50predictive about competency it probably isn't the underlying representation of number but it's time something
0:04:57about different aspects of the task like familiarity with the magnitude of and points
0:05:02and fluency with the ordered sequence which is not necessarily numerical or magnitude based in
0:05:07nature
0:05:09thanks for listening i hope you enjoy the paper that you're victory and if you
0:05:12have any questions or comments and forty hearing from you