Interislander Ferry

Ranking Score Explained

Kia ora, thanks for your interest in how we calculate an experience's ranking score. It's at the core of Rankers so I'm pleased you're curious.

The ranking score percentage is used to compare and sort experiences in ranking tables. It is not necessarily a direct measurement of the quality of a particular experience as rated by its customers. I've found it a useful tool to allow me to find the best experiences with confidence. But I've also found it important to read the customer reviews before making any final judgements!

We calculate an experience's ranking score using a multi-factor data model instead of a raw data average (mean). This model takes into account several important questions. For instance - is there a trusted body of reviews? What is the age of a review and is the review from a credible source?

Below you'll find details around some of the important factors that went into calculating the ranking score for Interislander Ferry.

If you have any questions or comments about our ranking score calculation please get in touch at info@rankers.co.nz. We don't believe this is perfect or complete so we're always interested in ways we might make improvements.

Cymen Crick

Rankers Owner

Valid Reviews

349 Valid Reviews

The Interislander Ferry experience has a total of 360 reviews. There are 349 valid reviews that are included when calculating the ranking score and 11 invalid reviews that are excluded from the calculation. Reviews can be excluded only when a reviewer is not verified or after an investigation by our team determines the reviewer is not genuine.

Below is the distribution of ratings for the 349 valid reviews:

Rating	Count
10/10	40	11%
9/10	81	23%
8/10	103	30%
7/10	62	18%
6/10	29	8%
5/10	16	5%
4/10	7	2%
3/10	5	1%
2/10	2	1%
1/10	4	1%

77.13% Average

The raw data average (mean) for all the Interislander Ferry valid reviews is 77.13% and is based on 349 valid reviews. This value is not used to calculate the ranking score and it only provided here as a comparison to the weighted average.

Face-to-Face Reviews

309 Face-to-Face Reviews

The Rankers team meets with travellers while they’re in New Zealand and conducts face-to-face surveys. These reviews, in our opinion, are the most trusted in the industry and represent a critical control sample. To our knowledge, we are the only travel review website in the world that has gone to this extent.

More about face-to-face reviews

Within the 349 valid reviews, the experience has 309 face-to-face reviews collected during interviews by our team.

Below is the distribution of ratings for the 309 face-to-face reviews:

Rating	Count
10/10	30	10%
9/10	70	23%
8/10	98	32%
7/10	58	19%
6/10	25	8%
5/10	15	5%
4/10	6	2%
3/10	4	1%
2/10	2	1%
1/10	1	0%

77.22% Average

The raw data average (mean) for all the Interislander Ferry face-to-face reviews is 77.22% and is based on 309 face-to-face reviews. This value is not used to calculate the ranking score and it only provided here for comparison purposes.

Weighted Average

73.56%

Rankers calculates a weighted mean as a base average on which we can improve. Individual review's ratings are given a weight based on several factors. The weight of a review determines the overall impact it'll have on the final weighted average.

Recent reviews have more weight as they are more relevant and reflect the experience as it currently operates. Over time reviews become less relevant and loose their impact on the ranking score.

Low rating reviews carry slightly less weight. This dampens the effect of very low ratings for every experience across the board. This is especially important when the experience has few reviews overall and a single negative rating can grossly mischaracterise an experience. Consistent poor reviews will still result in the experience receiving a comparitively low ranking score.

Credible sources provide reviews that can be trusted. If we have verified a reviewer is genuine via a face-to-face meeting then the review carries additional weight.

Reviewer	Rating	Age	Relative Weight
Rina	9/10	106 days	100%
edm	1/10	380 days	38%
Colin Barrow	9/10	441 days	89%
Pauline	6/10	594 days	70%
Megan	5/10	746 days	53%
Marjolaine Loitz	4/10	776 days	44%
Keli Knox	10/10	1111 days	35%
Yar	1/10	1325 days	8%
Pinocity	6/10	1690 days	5%
Helen Russell	10/10	1871 days	5%
NewZealander	10/10	2145 days	4%
Tommy Pickett	9/10	2968 days	3%
Tom Bennett	8/10	2972 days	3%
Jeny Smolders	9/10	2974 days	3%
Gregg Wagstaff	7/10	3199 days	2%
Lianne Ijlst	8/10	3227 days	2%
Samantha and Neis	8/10	3228 days	2%
Brandon Cassidy	7/10	3244 days	2%
Vic Baughen	9/10	3246 days	2%
Anders Frank	7/10	3250 days	2%
Dina Schurer	8/10	3251 days	2%
Kim Youngsub	9/10	3252 days	2%
DEBBIE LAMBERT	10/10	3256 days	2%
Gary Williams	8/10	3256 days	2%
Kimberley Gardien	8/10	3263 days	2%
Antoine	9/10	3284 days	2%
Judit Van lanen	9/10	3289 days	2%
Bjorn Nielsen	8/10	3291 days	2%
Joel Virtanen	9/10	3293 days	2%
Corbin Hure	7/10	3293 days	2%
Ron	6/10	3296 days	2%
Thomas Simeon	8/10	3296 days	2%
Suzannah Hill	8/10	3297 days	2%
Kallan Mrozek	9/10	3298 days	2%
Kees Mol	9/10	3302 days	2%
Kristal Lavender	10/10	3302 days	2%
Bastian Bley	9/10	3303 days	2%
Jasmine Rogers	3/10	3304 days	1%
Louis Nilsson	8/10	3308 days	2%
Tim	7/10	3308 days	2%
Jendrik	6/10	3308 days	2%
Katharina	7/10	3309 days	2%
Chris Valchero	9/10	3312 days	2%
Rulp Niet	8/10	3314 days	2%
Soeren Buchheister	9/10	3315 days	2%
Chas Bronson	8/10	3315 days	2%
Jakob Lovdahl	9/10	3317 days	2%
Alexandra Schmidt	10/10	3327 days	2%
Jade Williams	10/10	3328 days	2%
Sam Staines	10/10	3329 days	2%
Nickolas Jonkergouw	7/10	3333 days	2%
Kirsty Smith	10/10	3333 days	2%
Eva Hesse	10/10	3348 days	2%
celine gries	8/10	3348 days	2%
tinagermany111	8/10	3362 days	2%
Cassandra Geyer	8/10	3547 days	2%
Olivier Reculeau	8/10	3548 days	2%
Thomas Michel	5/10	3549 days	1%
Lisa Haedrich	5/10	3553 days	1%
Nadja Guiliani	8/10	3557 days	2%
Elbrich	8/10	3557 days	2%
Jamie Serieux	7/10	3560 days	2%
Adele Jacques	9/10	3561 days	2%
Daniel Weber	6/10	3563 days	1%
Emily Noyd	8/10	3565 days	2%
Aparna Gula	10/10	3566 days	2%
Sebastiaan	7/10	3568 days	1%
Andre	9/10	3569 days	2%
Benedikt Hang	7/10	3570 days	1%
Yannick	8/10	3570 days	2%
S Black	9/10	3571 days	2%
Paul Larauze	6/10	3574 days	1%
Florence	6/10	3575 days	1%
Sarah Kovacs	8/10	3576 days	2%
Frenziska Schmid	7/10	3578 days	1%
Maud Livolsi	7/10	3585 days	1%
Lewis Whittle	6/10	3587 days	1%
Lukas Seager	6/10	3587 days	1%
Andrea Tabaka	8/10	3594 days	2%
Tina Rust	8/10	3596 days	2%
Joel Papak	8/10	3598 days	2%
Clemence and Pedro	9/10	3599 days	2%
Doms Wahlelr	9/10	3601 days	2%
Josef Biller	8/10	3601 days	2%
Justine Hoffmann	8/10	3602 days	2%
Friederike East	7/10	3602 days	1%
Mark White	10/10	3603 days	2%
Briony	8/10	3606 days	1%
Gabriel Siibers	8/10	3606 days	1%
Henry Wichler	8/10	3607 days	1%
Kyle Johnson	9/10	3609 days	2%
Niels Wezenberg	7/10	3610 days	1%
John Hamilton	9/10	3610 days	2%
Brianna Burd	9/10	3610 days	2%
Jessica Ruhland	8/10	3611 days	1%
Stula Vladimir	10/10	3612 days	2%
Cosmo Hartuna	7/10	3614 days	1%
Roland Fischer	6/10	3614 days	1%
Ross Holmes	9/10	3615 days	1%
Tilman	9/10	3617 days	1%
Petru	7/10	3618 days	1%
Fero Saarinen	6/10	3619 days	1%
Lauren Thompson	8/10	3621 days	1%
Meilin	8/10	3624 days	1%
Jonas Hoerning	10/10	3628 days	1%
Vanesha Patel	6/10	3629 days	1%
Mauricio Daniele	9/10	3629 days	1%
Sara and Antoine	8/10	3631 days	1%
Clare Pickford	6/10	3631 days	1%
Daniel Hill	10/10	3632 days	1%
Moritz Braun	7/10	3648 days	1%
Grischa Rodust	8/10	3655 days	1%
Chalie Dotesek	9/10	3656 days	1%
Julien Lafeville	7/10	3660 days	1%
Julia Huesam	8/10	3660 days	1%
Alexandre	9/10	3664 days	1%
Kev Zarka	6/10	3665 days	1%
Markus Wabing	8/10	3668 days	1%
Gessica	6/10	3701 days	1%
Simon Quass	9/10	3705 days	1%
Barthelemy	7/10	3934 days	1%
Brita Topp	10/10	4277 days	0%
Laim Thompson	8/10	4277 days	0%
Adriana	10/10	4285 days	0%
Pavel Jarolimek	5/10	4285 days	0%
Leonie Moeller	6/10	4286 days	0%
Doreen Gendel	8/10	4287 days	0%
Carla Oyarzun	3/10	4290 days	0%
Paolo Cases	3/10	4290 days	0%
Wolfgang and Christine	8/10	4295 days	0%
Helen	8/10	4308 days	0%
Olivier Carval	9/10	4310 days	0%
Hirsch Svenja	9/10	4311 days	0%
Mahr Svenja	8/10	4311 days	0%
Anna Guzewiez	9/10	4327 days	0%
Pier Durand	8/10	4331 days	0%
Serena Poggioli	9/10	4331 days	0%
Wayne Schist	7/10	4331 days	0%
Margreth Lydie	5/10	4339 days	0%
Laura Pleumeekers	7/10	4353 days	0%
David Brooks	10/10	4356 days	0%
Adrien Godeloup	9/10	4365 days	0%
Bet Dreno	8/10	4366 days	0%
Joachim	1/10	4367 days	0%
Pioter Jurkowski	7/10	4367 days	0%
Thomas Roche	9/10	4369 days	0%
Brian	9/10	4428 days	1%
hendrik king	9/10	4551 days	1%
Kiki Wykstra	5/10	4661 days	1%
Galen Licht	4/10	4661 days	1%
Yu-Ti Chu	7/10	4664 days	1%
Ton Martens	7/10	4664 days	1%
Joshua Perry	8/10	4669 days	1%
Molly Ladd	8/10	4669 days	1%
Michael Nolan	9/10	4673 days	1%
Julian Roots	9/10	4673 days	1%
Florent Corino	9/10	4677 days	1%
Amiot Cyriane	7/10	4677 days	1%
Annika	7/10	4677 days	1%
Jonas Herrmann	7/10	4677 days	1%
Matthieu Daveou	8/10	4677 days	1%
Julien Panossian	6/10	4677 days	1%
Raoul Montestruer	5/10	4677 days	1%
Alessa Ndra	8/10	4683 days	1%
Bjorn Hedmark	5/10	4684 days	1%
Evyatar Tulipman	7/10	4686 days	1%
S Curry	10/10	4701 days	1%
Ingrid	9/10	4745 days	1%
Reinier Timmer	7/10	4745 days	1%
Moorman	8/10	4754 days	1%
Stefan Roth	9/10	4779 days	1%
David	9/10	4793 days	1%
kevindang	10/10	4946 days	1%
Ruben Kunze	4/10	5028 days	1%
Sebastian Hol	9/10	5034 days	1%
Dick Stewart	8/10	5043 days	1%
David Beaumont	9/10	5050 days	1%
Beyeler	10/10	5055 days	1%
Nikita Sue	9/10	5060 days	1%
Schweiger	10/10	5062 days	1%
Jan & Marian	10/10	5141 days	1%
Konny	9/10	5145 days	1%
Waldemar Schuler	8/10	5145 days	1%
jule	3/10	5159 days	1%
Jack Potman	8/10	5361 days	1%
Jon_and_Family	9/10	5373 days	1%
Walker	9/10	5376 days	1%
Andreas Blessing	10/10	5384 days	1%
Gema	7/10	5387 days	1%
Avry Fabrice	6/10	5392 days	1%
Diane Johnston	9/10	5397 days	1%
Javier Munoz	8/10	5397 days	1%
Ben Akin-Smith	8/10	5398 days	1%
K Wallis	9/10	5403 days	1%
khs	9/10	5404 days	1%
Emma Ducat	9/10	5404 days	1%
Mr and Mrs Lambert	8/10	5411 days	1%
Andrew Koster	7/10	5417 days	1%
Bakker	8/10	5417 days	1%
Kimberly St Louis	8/10	5418 days	1%
Roel Wesstra	8/10	5424 days	1%
Seifert	10/10	5424 days	1%
Derek Woodward	9/10	5426 days	1%
Fabi & Sabi	8/10	5427 days	1%
Rosey834	8/10	5494 days	1%
Pete & Chris	10/10	5694 days	1%
Tony Masters	9/10	5757 days	1%
Hershell	8/10	5761 days	1%
Mike Robinson	9/10	5762 days	1%
Brent S	2/10	5763 days	0%
Zara Leyden	9/10	5771 days	1%
Judith	7/10	5775 days	1%
anon	8/10	5776 days	1%
Pierre Pilon	8/10	5777 days	1%
Jenny Omb	1/10	5782 days	0%
Frei Urs	6/10	5783 days	1%
Bryan Keddie	9/10	5793 days	1%
Leanne Rogan	5/10	5793 days	1%
Joanne Clarke	8/10	5797 days	1%
Wolfgang G	9/10	5803 days	1%
Thomas Signes	7/10	5824 days	1%
menzel	10/10	5842 days	1%
graemeh1	9/10	5843 days	1%
klinger	10/10	5843 days	1%
gereldineb	8/10	5853 days	1%
jennyb	9/10	5857 days	1%
Frank de Voogd	8/10	5863 days	1%
Jean Paul Mesnage	9/10	5869 days	1%
Hansjoerg Ehrmann	5/10	5870 days	1%
Daniel Alonso	9/10	5871 days	1%
Nigel Petrie	9/10	5882 days	1%
Tracy & Peter Cassidy	8/10	5898 days	1%
miniappleses	8/10	5920 days	1%
Josie Boyle	7/10	6031 days	1%
JanneP	9/10	6101 days	1%
Mikey	9/10	6108 days	1%
SablotniD	7/10	6112 days	1%
WiebkeS	9/10	6119 days	1%
Tanya	5/10	6120 days	1%
Jan	6/10	6120 days	1%
Viola	8/10	6122 days	1%
RowanL	7/10	6123 days	1%
VickiEngland	8/10	6131 days	1%
TomC1	8/10	6136 days	1%
AndyK	9/10	6136 days	1%
TatiamT	9/10	6136 days	1%
GillianK	8/10	6138 days	1%
EelcoK	9/10	6138 days	1%
Michael	9/10	6142 days	1%
soccaplaya14	10/10	6142 days	1%
Eugene	7/10	6144 days	1%
John	6/10	6146 days	1%
Tony	8/10	6151 days	1%
Middleton	4/10	6152 days	1%
Elise	8/10	6153 days	1%
Marie	8/10	6153 days	1%
ThomasS1	10/10	6158 days	1%
RasmusB	4/10	6160 days	1%
Simon	8/10	6165 days	1%
Phil&Joe	10/10	6167 days	1%
Marcus	7/10	6167 days	1%
Andre	7/10	6169 days	1%
Iris	9/10	6171 days	1%
Carla	7/10	6171 days	1%
Sandra	8/10	6175 days	1%
Schaffluber	10/10	6176 days	1%
Hayley	5/10	6177 days	1%
Con	2/10	6221 days	0%
felix	7/10	6222 days	1%
melissa	10/10	6228 days	1%
John B	5/10	6231 days	1%
Gemma	7/10	6269 days	1%
Henry	7/10	6270 days	1%
Antonella	10/10	6277 days	1%
Michelle	8/10	6277 days	1%
Laura	7/10	6286 days	1%
Sarah	8/10	6300 days	1%
Katerina	7/10	6321 days	1%
Erin	3/10	6321 days	1%
Mike Knight	9/10	6342 days	1%
Bronagh Mcartan	8/10	6351 days	1%
Dave	8/10	6362 days	1%
fgregory	10/10	6365 days	1%
Rhea	6/10	6411 days	1%
Georgina Mulligan	8/10	6422 days	1%
Karen C	7/10	6434 days	1%
Edmund Hillstone	10/10	6452 days	1%
Toby	6/10	6475 days	1%
Jennifer Baulch	9/10	6479 days	1%
Susan	8/10	6483 days	1%
Hoetnagels	7/10	6486 days	1%
Alan Bellerby	8/10	6489 days	1%
Sanne Jonker	7/10	6490 days	1%
Renske Tehurne	8/10	6494 days	1%
Benjamin Krein	7/10	6494 days	1%
Anne and Derek	8/10	6495 days	1%
James Davies	7/10	6495 days	1%
Naomi Horton	8/10	6496 days	1%
Roger Repolusk	8/10	6500 days	1%
Tony Wicks	6/10	6500 days	1%
Nancy Dol	8/10	6500 days	1%
Kristine	10/10	6500 days	1%
Kathy Hawey	9/10	6502 days	1%
David Buckley	8/10	6503 days	1%
Lena1	6/10	6503 days	1%
John Woodrow	8/10	6504 days	1%
Carmen Dolny	10/10	6504 days	1%
Haemnerli	8/10	6508 days	1%
Carla	8/10	6515 days	1%
Jim Curley	8/10	6515 days	1%
paulonline	7/10	6521 days	1%
Bex	6/10	6530 days	1%
Jenny Hulsebosch	8/10	6531 days	1%
Melissa Steedman	8/10	6542 days	1%
Tim	7/10	6543 days	1%
Falk Seidel	7/10	6546 days	1%
Hans Olthof	8/10	6546 days	1%
Anu	9/10	6549 days	1%
Anneli	6/10	6551 days	1%
purplekat99	10/10	6559 days	1%
Connor	10/10	6572 days	1%
Ad	7/10	6572 days	1%
Ann Westmacott	5/10	6577 days	1%
Paul Cowie	8/10	6578 days	1%
Ewen Maclean	8/10	6578 days	1%
Sarah Wilton	5/10	6578 days	1%
Arend v Dyn	7/10	6580 days	1%
Linda	8/10	6584 days	1%
Fiona	7/10	6584 days	1%
Ann	7/10	6585 days	1%
ranker_584	9/10	6588 days	1%
Christine	7/10	6588 days	1%
Nina	9/10	6588 days	1%
Anthony	7/10	6593 days	1%
Tom Clements	7/10	6593 days	1%
ranker_46	8/10	6705 days	1%
Pat Brewster	8/10	6705 days	1%
FrankOosterwijk	6/10	6790 days	1%
Kim	8/10	6790 days	1%
Helen	7/10	6821 days	1%
Heather	9/10	6821 days	1%
Helene	9/10	6833 days	1%
John	7/10	6833 days	1%
Giancarlo	6/10	6833 days	1%
Annette	4/10	6857 days	1%
John	5/10	6857 days	1%
Duncan	9/10	6862 days	1%
Jen	4/10	6873 days	1%
Rolf	8/10	6881 days	1%

Adjustments

Several adjustments to the weighted average are added to improve relevancy and credibility. These adjustments apply equally to all experiences that meet the criteria.

Sample Size Adjustment

No Adjustment

A reasonable number of reviews are necessary in order for the average to be credible and for an experience to take a prime position within the ranking tables. As such, experiences with only a few reviews have a moderated score. This does not mean that the experience or the reviews can't be trusted. The Interislander Ferry experience has plenty of reviews and does not meet the criteria for any adjustment.

Recent Reviews Adjustment

-1.95% Adjustment

There may be an adjustment if this experience hasn't received any reviews within the last 42 days. However the Interislander Ferry experience does not meet the criteria for any adjustment.

In addition, an experience's ranking score may be adjusted for each day there is no new ranking. After 1 day the adjustment comes into effect. The maximum number of days that can be adjusted for is 200 days. Due to the seasonal nature of many businesses, this adjustment is applied dynamically throughout the year.

The Interislander Ferry experience has been adjusted for 96 days. Adjustments are according to the following table.

Days	Adjustment
…	…
93	-1.89%
94	-1.91%
95	-1.93%
96	-1.95%
97	-1.97%
98	-1.99%
99	-2.01%
…	…

Balancing Adjustment

6.15% Adjustment

Every experience's review score is adjusted to balance out the disproportional number of negative reviews that are contributed.

You won't be surprised to learn that disgruntled customers are more likely to leave a review than happy ones. They are motivated to share their experience and warn others. We consider this a good thing and it's why reading the reviews is important. However we've learned it can misrepresent the experience in a more overall sense.

We apply a balancing adjustment to counteract this effect and ensure the ranking score is a more fair representation of the experience. This adjustment is applied equally to all experiences.

Final Ranking Score

78%

The final ranking score once any adjustments, ratings, and rounding has been applied. This value is recalculated each day and a short rolling average is applied. Therefore it may not be precisely accurate based on the other values presented.