Graphs Basics, Formats, Oral vs. Written, Etc .

Lecture 04 TECHNICAL COMMUNICATONS Spring 2014 - Althoff GraphsBasics, Formats,Oral vs. Written, Etc. Fig. 1.Grasshopper sparrow (GRSP) territory density in relationship to vegetation density (VOR = visual obstruction readings on Fort Riley, Kansas, 2005.

Figures • Meant to ____________ or present technical info that may not be easy to do with text (i.e., lots of text) • Definitely the old adage “a picture is worth a 1,000 words” applies to use of Figures. • Typically, legends for Figures are at the bottom of the graph, drawing, schematic, picture, etc. vs. the top for Tables.

Figures: general tendencies • Seldom used in _____________ • Frequent in _______________ ex. Country  state/region…. Multiple study sites Sometimes to show topography or vegetation types (common in oral presentations, rare in written) • If in __________, usually diagram of experimental design or sampling design or special equipment • Most common in _____________ • Almost never in ______________ unless presenting a new model or process/theory

MAP FIGURES • Include ______ • Include ______ • Minimize clutter • 1-2 font types • max • for written, think • B & W

For oral • presentations... • _____ is often a • good option MAP FIGURES

SCHEMATIC FIGURES • be ________ with • fonts • try to keep things • to relative scale • __________ balancE • detail with simplicity

Figures--schematics: oral presentations • If “complex”…then start with basic or first type then “_____” from one slide to the next. • May require lots of verbal ‘add on’ commentary to be sure audience understands what you want them to understand or recognize • Seldom can do “add” approach for a written publication/report.

1 Point-Intercept • Measures distance (length) of plant coverage along line • Or, measure GAP between plants (estimate of bare ground) • Gives estimate of coverage…. improvement over point-intercept method SCHEMATIC FIGURES ORAL

2 Point-Intercept Line-Intercept • Measures distance (length) of plant coverage along line • Or, measure GAP between plants (estimate of bare ground) • Gives estimate of coverage…. improvement over point-intercept method SCHEMATIC FIGURES ORAL

SCHEMATIC FIGURES 3 ORAL Prosser, C.W., K.M. Skinner, and K.K. Sedivec. 2003. Comparison of 2 techniques for monitoring vegetation on military lands. Journal of Range Management 56:446-544. Point-Intercept Quadrats Line-Intercept • Quadrats every 5 m • 0.25 m2 frame for forb frequency, and presence/absence • 0.1 m2 frame set inside 0.25 m2 frame for grass (graminoid) frequency • Compared results to point-intercept method *Done in “transitional” grasslands: between tall- and mixed grass prairie

PHOTO FIGURES • label in the “image” • if directing reader • to specific feature • good quality • photos are • essential • Figure legend ____ • important than you • would think…. Fig. 1. Residual tank tracks evident by earlier green-up of grassland patches in spring than areas not subjected to crushing of vegetation the prior to green –up.

WRITTEN A B Fig. 1. Pre-rehabilitation conditions (A- September 2004) vs. post-rehabilitation (B-July 2005) on a training site on Fort Riley, Kansas. Off-road vehicle tracks visible in 2004 were “filled in” predominately by grasses and forbs in 2005.

ORAL September 2004 July 2005 (10 months later) The off-road tracks visible in 2004 (L) aremostly grass/forb covered by July 2005 (R).

Figures that are data plotted or graphed • Clearly label ____ and _____ --including ______ • May need _____ to symbols/codes used either on the graph itself or in the figure legend…or both • Keep ____________ to 2 or less • Font sizes depend on space and importance—but ___ _______________…especially for oral presentations • _______________________ for _____ presentations • Carefully choose when to “connect the dots”

Figures that are data plotted or graphed…con’t • Almost always have ______________________ variable on the X-axis • Almost always have the ____________________ variable on the Y-axis exception would be if dealing with a “vertical” measure for the predictor variable: ex: height in tree depth in the ground

Other Figure-related guidelines on data plotted or graphed • Do _____ have to start an axis at zero (either X- or Y-) • If multiple graphs in a series, then be consistent with the scale (otherwise…misleading if not noted in Figure legend) • Avoid too much on a single graph of data—may need to be multiple years or study sites on separate “identically” formatted graphs • Sometimes 2 Y-axes are appropriate—excellent way to show 2 different response variables • Careful with _________________—can appear to be missing if no notation

Connecting the dots….good or bad?

Multiple years….too much on one graph?

WRITTEN Fig. 19. Nematode family richness (weighted means with 90% confidence intervals) of soil samples versus the disturbance index (2002: rs =-0.68**, 2004: rs =-0.78***), on Fort Riley, Kansas.

ORAL 2002: rs =-0.68**, 2004: rs =-0.78***.

Example: multiple Y-axes

In summary… • Keep it __________ • Keep it __________ as possible • Keep it __________ • Be sure it does convey a “picture”—even if ______ (vs. photograph)

Graph types for Data • Bar (histogram): vertical & horizontal • Scatter plot • Plots with “lines” = line graphs (i.e., connect the dots or trend lines) • Plots with error, range bars • Pie charts • Etc.

WRITTEN Fig. 1.Grasshopper sparrow (GRSP) territory density in relationship to vegetation density (VOR = visual obstruction readings on Fort Riley, Kansas, 2005.

ORAL Plant Density (biomass) vs. Territory Density

Graphs Basics, Formats, Oral vs. Written, Etc .