We thank to the Reviewer for her positive opinion.  We respond to her second review comments in following.

R: -Abstract: The bias against small, low albedo objects by the visible surveys cannot be *that* small.  We know this to be the case because the sample of ~2000 asteroids with optical/near-IR taxonomic classifications shown in Figures 1 and 2 of Mainzer et al. 2011 ApJ 741, 90 is clearly missing the population of smaller, low albedo C-complex asteroids that dominate the Main Belt.  These objects, smaller than ~25 km and with albedos <~.08, make up the majority of Main Belt asteroids that we can see in Masiero et al. (2011).  Yet there is a big hole in Figures 1 and 2 of the taxonomy paper - because these small, low albedo objects simply are not detected by the visible surveys. To illustrate the issue, I've made a graphic that show the ~130,000 Main Belt asteroids from Joe's paper that have albedos, with the ~2000 taxonomically classified asteroids overplotted in cyan.  Running medians are overplotted for both groups - those with optical/NIR taxonomic classifications, and those
that did not have them.  You can see that there is a big bunch of asteroids in the 5-25 km with low albedos that are not represented in the visible/NIR sample that have taxonomic classifications. The general population of NEOWISE-selected objects shows no significant variation in albedo v. diameter, as we expect from blackbody physics, which suggests that infrared flux is only weakly proportional to pV. It's also worth keeping in mind that the ~130,000 objects in Joe's paper do not include the ~30,000 NEOWISE discoveries that do not yet have optical follow-up, and hence do not have albedos - these objects will tend to be small and dark. Even if we adjust some of the H values for the cyan points down by 0.2-3 mag, there is still a big chunk of small, darker asteroids that are missing from taxonomically-classified samples, and this will bias the median albedo for a given taxonomic class up.  In the case of the C-complex asteroids, we don't even have enough of a taxonomically
classified sample below ~20-30 km to definitively say what the trend in size v. albedo is at all.  I've also attached similar plots for the Hildas (from Grav et al. 2012) and NEOs (from Mainzer et al. 2011 ApJ 743, 156).  The running median for the Jovian Trojans looks similarly flat (from Grav et al. 2011).  

A: The referee’s comments above are on the bias against small, dark (C and similar dark classes) objects in the sample of spectroscopically classified asteroids, but they don’t give a constraint on the magnitude of a potential bias towards higher albedos *within* the S complex in the size range 5-25 km that we investigated.  We mention in the paper the possibility that the albedo difference of 0.03 between small and large (divided at diameter 25 km) S types we see is caused by an observational bias against lower albedos within the S class, but we don’t have a ground to estimate its magnitude, so it remains a hypothesis.

R: In the abstract, I suggest the following change of wording (indicated with ***) to the sentence beginning "The difference will have to be confirmed and explained***. We speculate that it may be either a real size dependence of surface properties among the different asteroid types, or (more likely) a size-dependent bias in this optically-selected sample of asteroids.***  

A: We have changed the sentence in the abstract as follows: „The difference will have to be confirmed and explained; we speculate that it may be either a real size dependence of surface properties of S type asteroids or a small size-dependent bias in the data (e.g., a bias towards higher albedos in the optically-selected sample of asteroids).“

R: … A trend of the mean of the preliminary WISE albedo estimates increasing with asteroid size decreasing from D~30 down to 5 km (for ***optically selected and taxonomically classified S-types only; infrared-selected samples do not show this trend***) shown in Mainzer et al. ***may be in part*** due to the systematic bias in the MPCORB absolute magnitudes that progressively increases with H in the corresponding range H=10-14."  

A: We think that the sentence as we have it there in the abstract describes correctly what we have found.

R: -On page 6: Please include a reference to Tedesco et al. (2006; AJ 123, 1056) instead of Ryan & Woodward (2011).  In Mainzer et al. 2011 ApJL 737, 9, we found that the Ryan & Woodward results actually have a systematic offset relative to radar-measured objects that the original Tedesco et al. results do not have.  It would actually be worse for observers to use their values, so it is best to stick with the original Tedesco reference.   

A: We have added the reference Tedesco et al. (AJ 123, 1056, 2002 - not 2006) there to the sentence on page 6.  Re. your proposed removing of the Ryan and Woodward (2011) reference: If there is present a bias in their results from Spitzer data (just by Ryan&Woodward, or all results from Spitzer data?), it might be indeed good not to mention the survey observations from Spitzer there on page 6 at all.  Is there a reference showing the systematic bias in their results you mention?

R: -Thank you for the explanation of why Shevchenko & Lupishko (1998) is used for mean visible colors.  That makes sense. However, I do question whether the claimed 0.05 mag spread in V-R for S-complex asteroids is really that small...that seems awfully low.  Perhaps the 0.05 mag is actually the standard deviation of the mean, rather than the standard deviation of the distribution of V-R values?  

A: The 0.05 mag is indeed the dispersion (standard deviation) of the (V-R) values in the S-complex.  It is actually a realistic value; we have seen similar dispersions for the (V-R) color index among S types estimated by others.

R: -It is important to include the ~0.1 mag systematic error due to the unknown color term when quoting the revised estimated H errors.  This is what I would use if I were attempting to apply an offset in H for an object for which V-R color was not directly measured. For fitting an albedo for an individual object, I don't know whether an asteroid is S-complex or C-complex without colors or spectra, so I have to assume that I've either guessed right (in which case there is 0 additional error from the color correction), or wrong (in which case there is a ~0.1 mag error from an incorrect color correction). One cannot apply an average error of 0.055 to an individual object - it is either 0 or 0.1.  The conservative approach is to assume 0.1 mag.   

A: Yes, if one doesn’t know if a given asteroid is S-complex or C-complex, it might be reasonable to apply a correction to its catalog H value smaller by ~0.045 mag (which is a half of the difference between the catalog H offsets of S/S-like and C/C-like types of 0.09 mag we found among large asteroids) than our estimated correction.  We think that it is obvious from what we present in Section 3.  As an application of the H correction may or will depend on a particular asteroid sample that a user works with, we present our results as they are and leave applying possible further smaller corrections to the users.

R: -page 52: There seems to be some misunderstanding (perhaps not on the part of the authors, but certainly on the part of the other referee) about how the NEATM code was implemented for WISE.  In answer to R1, we do not treat H as a "free parameter".  We treat it as an independent measurement with an associated error (usually taken to be 0.2-0.3 mag).  This is not the same thing as treating H as a free parameter.  It is treated the same way as the other four WISE magnitude measurements, which each have an associated error.  The code does a least-squares fit to determine beaming, diameter, visible albedo, and infrared (3-4 um) albedo. The error bars on each of these four free parameters are determined from Monte Carlo trials that allow the four WISE measurements + H to vary within their error bars (W1+dW1, W2+dW2, W3+dW3, W4+dW4, H+dH). Please reword the paragraph beginning "A reason for this modification..." as follows:

"A reason for this modification of the Harris & Harris method was that the NEATM modeling employed in Masiero et al. (2011) and Mainzer et al. (2011b) uses a least-squares minimization to the four WISE magnitudes as well as the H value.  All five measurements are allowed to vary within their error bars; in the case of the H values, the error on H was assumed in most cases to be 0.3 mag as described in Mainzer et al. 2011 ApJ 736,100.  Thus, one must take care in applying Equation 5 to account for the error on H when attempting to convert an offset to H into a corresponding change in albedo."  

It is not necessary to cite personal communications here - the use of the least-squares fitter with the five measurements (W1+dW1, W2+dW2, W3+dW3, W4+dW4, H+dH) is clearly explained in Mainzer et al. (2011 ApJ 736, 100). Coauthor Al Harris was the referee on that paper.  

A: We found that for most of the asteroids (>90%), your tabulated H values (which we obtained from your listed D and p_V values) agree with the MPC H values to 0.01 mag.  Only for <10% do they differ at all.  So, it appears that you allowed the H value to adjust to best fit in only a fraction of cases.

We have changed the paragraph on page 52 so that it describes the reason for our modification of the Harris&Harris method that uses the listed D values rather than the unavailable (as they are not listed in your data files of Masiero et al. 2011 and Mainzer et al. 2011b) your final H values.

R: -In the following paragraph on p52, there again seems to be some misinterpretation of the errors on WISE diameters.  As described in Mainzer et al. 2011 ApJ 736, 100, all WISE diameters should be taken to have a minimum systematic error of 10% (and possibly more when objects are very far from round).  The errors quoted in the tables are the formal errors resulting from Monte Carlo trials that vary dW1, dW2, dW3, dW4, and dH.  These formal errors should always be added in quadrature to the minimum estimated systematic error of 10%.  The 10% most probably comes from small errors in our knowledge of the appropriate color corrections to use, or in our knowledge of the absolute transmission curves for each band. The errors in dD for individual objects quoted in the WISE thermal fit tables are not underestimated - you're just not using the errors the right way here. You will need to recalculate your Harris & Harris corrections accordingly, and reword the paragraph. I suggest the
following wording changes (also, please cite the following Grav papers which performed similar procedures for the Trojans and Hildas): 

"The dD values given by Masiero et al. (2011), Mainzer et al. (2011b), Grav et al. (2011,2012) present the formal errors derived from Monte Carlo trials that varied the WISE and H magnitudes by their errors.  These formal errors should be added in quadrature to the typical systematic error of 10% described by comparing WISE thermal model results to objects with well-known diameters (Mainzer et al. 2011 ApJ 736, 100).  The WISE data modelers assumed a 0.2 or 0.3 mag uncertainty in the MPCORB H values that were used to compute albedo (Masiero et al. 2011; Mainzer et al. 2011b; Grav et al. 2011; Grav et al. 2012).  Since all our H estimates have uncertainties <=0.2 mag, random errors of our revised albedos should be lower than or at worst equal to the dpV values calculated by these authors."

A: We list the realistic errors (computed from quadratically added the formal error and the systematic error) for both the WISE diameter and albedo values in Table 4 now.  Using the realistic WISE delta D values and our delta H values, we have computed the uncertainties of our revised p_V values; a column with the delta p_V_Revised added there to Table 4.  The paragraph on page 52 changed accordingly.

R: Also, please note that we all (me, Joe and Tommy in our various papers) updated all of our H values using the LCDB.  Please amend your footnote accordingly on p. 53.  

A: The paragraph on pages 52-53 to which the footnote was attached has been changed (see above) and the footnote commenting on H data from the LCDB has disappeared.  Anyway, we point out again here that most of the H values in the LCDB were actually taken from the MPCORB so if you take the LCDB H values, you are actually still using MPC H values for most of the asteroids, not replacing them with any better values.

R: -Conclusions: The sentence "We found that the trend in albedo..." should be reworded as follows: 

"We found that the apparent trend of increasing albedo with decreasing size for the optically-selected sample of asteroids with taxonomic classifications only shown in Mainzer et al. 2011a is mitigated in our sample when our corrected H values are used. Nevertheless, taxonomic classifications for more small, low albedo objects are needed to fully characterize the trend."

A: We have reworded the second sentence in the Conclusions section.